The Journal of Industrial and EnQineering Gnemistry
Pub l i s h e d b y T H E A M E R I C A N C H E M I C A L S O C I E T Y
A T E A S T O N , P A .
Volume VI F E B R U A R Y , 1914 No. 2
BOARD OF EDITORS E ditor: M . C. W h i t a k e r
A ssista n t E ditor: L e o l a E . M a r r s
Associate Editors: G . P . A d a m so n , E . G . B a ile y , H. E . B a rn a rd , G . E . B a rto n , A . V . B le in in ge r, W m . B r a d y , C . A . B ro w n e, F . K . C am e ro n , F . B . C a rp e n te r, C . E . C a s p a ri, V . C o b le n tz , W . C . G eer, W . F . H illeb ra n d , W . D . H orne, T . K a m o i, A . D . L ittle , C . E . L u ck e , P . C . M c llh in e y , J. M . M a tth e w s , T . J. P a rk e r, J. D . P en n o ck , W . D . R ich a rd so n , G . C . S to n e, E . T w itc h e ll, R . W a h l, W . H . W a lk e r, W . R . W h itn e y , A . M . W rig h t.
P u b lish e d m o n th ly . S u b sc rip tio n price to n o n -m em b ers of th e A m erican C hem ical S o ciety , $6.00 y e a rly . F o reig n p o stag e, sev en ty -fiv e c en ts, C a n a d a , C u b a a n d M exico e x cep ted .
E n te r e d as Seco n d -class M a tt e r D e cem b er 19, 1908, a t th e Post-O ffice a t E a s to n , P a ., u n d e r th e A ct of M a r c h 3, 1879.
C on tributions sh ou ld be ad d ressed to M. C. W hitaker, Columbia U n iv e r sity , N ew York City
C om m unications c o n c e r n in g a d v e r tise m e n ts sh ou ld be se n t to T h e A m erican C h em ical S o c ie ty , 4 2 W est 39th S t., N ew York City S u b scrip tio n s and c la im s io r lo st c o p ie s sh ou ld be referred to Charles L. P a rso n s, B ox 5 05, W ashington, D. C.
Es c h e n b a c h Pr i n t i n g Co m p a n y, Ea s t o n, Pa.
T A B L E OF C O N TEN TS Ed ito r ia ls:
T he Invention of C elluloid... 90
Or igin al Pa p e r s: T he Com position of P ain t Vapors. B y H enry A. G ard n er... 91
M etallography as Applied to Inspection. B y W irt T assin ... 95
M ahone Petroleum . B y Charles F. M a b e ry ... 101
T he Preparation of M etallic C obalt b y Reduction of the Oxide. B y H erbert T . K alm u s... 107
Oxides of Cobalt. B y H erbert T . K alm us... 115
The A nalytical Constants of H ydrogenated Oils. B y Carleton E llis ... 117
The Chem istry and Properties of Glycerophosphates (Glycerinophosphates). B y Gaston D u B o is 122 T o xicity of Various W ood Preservatives. B y C . J. Hum phrey and R u th M . F lem in g... 128
A R apid M ethod for Determ ining the Percentage of Casein in M ilk. B y W . O. W a lk e r... 131
I. A N ew E lectrically Controlled and T im ed Asphalt Penetrometer. II. T h e E ffect of Penetrations of Variations in Standard Needles. B y Hermann W . M a h r... 133
An Apparatus and M ethod for Determ ining the H ard ness of B u tterfat. B y A . E Perkins... 136
Influence of Sm all Am ounts of E th y l Alcohol on F er m entation in Cane Sugar Syrup. B y C . B . Cochran and J. H . P erk in s... 141
Labo rato ryan d Pl a n t: Filter Presses. B y E . J. Sw eetlan d ... 142
Improvised M ine Fires on an Experim ental Scale 146 A Shaker for the M echanical A nalysis of Soil. B y Freeman W a rd ... 147
Ad d r esses: The Present Statu s of the W ood Turpentine Industry. B y E. H. French and James R . W ith ro w ... 148
Chem istry as Affecting the Profitableness of Industry. B y G. W . Thom pson ... 152
Per k in Me d a l Aw a r d: Chairm an’s Address. B y G ustave W . T h o m p s o n .... 155
Presentation Address. B y Charles F. Chandler 156 Address c f Acceptance. B y John W esley H y a tt 158 Personal Reminiscences. B y F ran k V anderpoel 161 Cu r r en t In d u str ial Ne w s: E valuation of Pulp W o o d ... 163
Progress in the Fixation of N itrogen in S c a n d in a v ia ... 163
Standard Specifications for the P u rity of R aw Linseed Oil from N orth Am erican S eed ... 164
Uranium, Radium and Vanadium R e p o rt... 164
T he Approxim ate M elting Point of Some Commercial Copper A llo y s ... 164
Bureau of M ines B u d g et... 165
Platinum Deposits in G erm an y ... 165
U. S. M ineral Production, 19 12 ... 165
Oil-Hardening P lant in N o rw a y ... 165
Concentrated N itric A cid in N o rw a y ... 165
Proposed Beet-Sugar F acto ry for C h ile ... 166
Production of Portland Cem ent in 19 13 ... 166
N atu ral Gaseous M ixtures R ich in H eliu m ... 166
No tesand Co r r esp o n d en c e: Purificaticffi of W ater b y Adsorption. Prelim inary Announcem ent... 166
N ote on Certain Unpublished W ork on E lectrolysis Using Supported M ercury K a th o d e ... 166
Synth etic R esin s... 167
O zon e... 170
R apid Determ ination of Copper in Steel, C ast Iron and A llo y S tee ls... 170
International E lectrical Congress, J 9 15 ... 171
Spring M eeting of the Am erican Chemical S o c ie ty .. . . 171
Bureau of Standards’ Analyzed Sam ples... 171
Synthetic Resins— C orrection ... 171
Vegetable Oils E xported from China, 19 12 ... 171
Annual Tables of Constants, E tc., Vol. I l l ... 171
Per so n al No t e s... 172
Book Re v ie w s: D ictionary of Applied Chem istry; Transactions of the Am erican In stitu te of Chem ical Engineers; General M etallurgy; Plantation W hite Sugar M anufacture; M etallurgical A nalysis; R eview of the Exam ination of W ater and W ater Supplies; Chem ical Technology and Analysis of Oils, F ats and W a x es... 173
New Pu b l ic a t io n s... 177
Re c e n t In v e n t io n s... 178
Ma r k e t Re p o r t... 180
go T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y V o l. 6, N o. 2
EDITORIALS
T H E IN V E N TIO N O F C E L LU LO ID .1
N e v e r h as th e P e rk in M e d a l b een b e tte r aw ard ed th a n to Jo h n W e s le y H y a tt. H e c re a te d a d is tin c tly A m e rica n in d u s try , ch em ical in its v e r y essence, a lth o u g h th e in v e n to r n e ve r claim ed to be a ch em ist.
H e n o t o n ly in v e n te d th e fu n d a m e n ta l p rin cip le on w h ich th is im p o rta n t in d u s try is b ase d , b u t he g a v e his fe rtile in v e n tiv e gen iu s an d th e b e tte r p a rt of his life to th e d e v e lo p m e n t of th e m a n y d e ta ils w h ich b u ilt up th e te ch n iq u e o f cellu lo id.
T h e te ch n iq u e of cellu lo id is s tr ik in g ly d ifferen t fro m th a t of ru b b er and all o th er p la stics. T h is ex p la in s w h y ru b b er te ch n o lo g ists o rd in a rily fa il w h en th e y a tte m p t c e llu lo id m a n u fa ctu rin g . I t p ro vid e s an excusejW hy th e h a rd ru b b e r concern s of th is co u n try fa ile d to see th e com in g im p o rta n ce of cellu lo id w hen th e n ew m a terial w as offered to th em .
I b e lie v e it w as R u d y a rd K ip lin g w h o, in one of his w ritin g s, refers to a fisherm an w ho w as s p e c ia lly su ccessfu l b ecau se “ he co u ld th in k as a cod-fish w o u ld t h in k .” I h a v e o b serve d in m eetin g cellu lo id or r u b b er m a n u fa ctu re rs th a t th e fo rm er ca n n o t th in k b u t
“ ce llu lo id ,” an d th e la tte r “ r u b b e r ,” and are m uch a t sea w hen th e y are co n fro n ted w ith th e te ch n iq u e of a n ew p la stic.
T h e h isto ry of th e d isc o v e ry an d in d u stria l d e v e lo p m en t of cellu lo id b y H y a t t h as b een d escrib ed in d eta il b y E . C . W o rd en , in “ T h e N itro ce llu lo se I n d u s tr y ,”
V a n N o stra n d , N e w Y o r k , 1 9 1 1 .
■ I m a y m en tion here, fro m co n v e rsa tio n s w ith th e in v e n to r h im self, th a t cellu lo id an d th e cellu lo id in d u s try w ith all th a t it im plies, a fte r all m ea n t m erely a b ig p aren th esis in th e life o f H y a t t in his q u est of a p e rfe ct b illia rd b all w h ich w o u ld rep lace th e exp en sive iv o r y a rticle . T h is is so tru e t h a t ev en d u rin g his la te r y e a rs, w hen he is w ell in th e seven ties, he h as sp e n t co n sid erable tim e in th e s tu d y of o th er p la stics in his e ffo rt to s till fu rth e r p e rfe ct b illia rd balls. C e l
lu lo id an d th e cellu lo id in d u s try are b y no m eans th e o n ly in v e n tio n s w h ich H y a t t h as to his cre d it; th e fam o u s H y a t t R o ller B e a rin g w h ich h as d ev elo p e d into a larg e an d su cce ssfu l m a n u fa ctu rin g en terp rise, his m eth o d s o f w a te r p u rifica tio n (w ith Isa ia h S. H y a t t ) , his p rocess for cru sh in g su gar can e, an d his m a n y o th er p a te n ts te s tify to th e a b u n d an ce as w ell as th e d iv e rs ity of his in v e n tiv e a ch ie vem e n ts.
T h e in v e n tio n o f cellu lo id is an e x ce lle n t exam p le of h ow som etim es it is a real a d v a n ta g e fo r a m an of gen iu s n o t “ to k n o w to o m u c h ;” n o t to be h am p ered b y to o m uch b o o k k n o w le d g e if th e la tte r te n d s ''to p e tr ify th e m ind in to a to o one-sided p o in t of view . In all his w o rk H y a t t ’s k een o b servin g m ind w as his sole gu id e . H e trie d th in gs fo r him self. H e did n ot re ly o v erm u ch on w h a t oth ers to ld him to be th e fa c ts , or on w h a t w as w ritte n in b ooks. H e .w anted to be his ow n “ a u th o r ity .” H e h a d fo u n d b y ex-
1 T h e P erk in M edal fo r v alu ab le researches leading to th e e sta b lish m e n t of in d u strie s w as a w ard ed on J a n u a ry 2 3 rd to M r. H y a tt. A full re p o r t of th e m e e tin g is p u b lish ed in th is issue of T h i s J o u r n a l .
perien ce th a t th e re are m a n y th in g s p rin te d in books and ch em ical tre a tise s “ th a t a in ’t s o .”
H e th u s d isco ve red th e im p o rta n t fa c t, on w hich th e w hole cellu lo id in d u s try is b ased, t h a t a m ix tu re of n itro cellu lo se, cam p h o r and a sm all a m o u n t of alco h o l, w hen p ro p e rly p rep ared , b ecom es th e rm o p la stic. In o th er w ords, it b ecom es so ft w hen h eated , can be m old ed in a h y d ra u lic press, and a fte r cooling to o rd in a ry atm o sp h eric pressure, it b ecom es again h ard and stron g.
H is p redecessors .all used n itro cellu lo se in presence of r e la t iv e ly la rg e a m o u n ts of so lv e n ts, and used a so lu tio n , or a r e la tiv e ly so ft m ass, fro m w h ich th e so lv e n ts w ere le ft to e v a p o ra te . T h is n o t o n ly m ean t a co n sid e rab le loss of so lv e n ts, b u t re stricte d en o r
m o u sly m a n y po ssible te ch n ica l a p p licatio n s. T h e m ass sh ru n k in th e a c t of d ry in g , an d ra p id m old ing w as im p ra c tic a l, if n o t to t a lly im possible.
Som e of his predecessors h a d e v e n used cam p h o r in th e ir so lu tio n s, a lth o u g h H y a t t k n e w n o th in g a b o u t th is u n til it cam e o u t la te r in his p a te n t su its. B u t his predecessors h ad used cam p h o r m erely as a n y o th er so lv e n t. T h e y h ad fa ile d to o b serve or to grasp th e g re a t te ch n ica l im p o rta n c e of th e fa c t th a t c a m p h o r co u ld m ake a solid so lu tio n w ith n itrocellu lose and pro d u ce a th e rm o p la stic m ass.
T h is see m in g ly sim p le o b se rv a tio n m igh t h a v e le ft v e r y little im p rin t on a n y o th er b u t th e a c t iv e ly c o n s tr u c tiv e m ind of a H y a tt. H e sa w r ig h t a w a y th a t fro m th a t m o m en t on, he cou ld e m p lo y p u r e ly m ech a n ical m eans fo r m old in g ra p id ly and e ffe c tiv e ly , and d evelo p th e te ch n iq u e of n itro cellu lo se p la stics, for p u rp o ses n eve r d re am t of before. T h e p rin cip le w as sim p le an d th e a v a ila b le m eth o d s seem ed sim ple en ou gh . B u t as u su al, w h en one tries a process co m m e rcia lly , it w as fo u n d th a t th ere w ere endless d eta ils w hich co n sp ire d to render th e in d u stria l a n d co m m ercial d e v e lo p m e n t a fa r m ore d ifficu lt p ro b lem th a n th e m ere d isc o v e ry of the new p rin cip le in th e la b o ra to ry . H ere th e w h ole pro b lem m igh t h a v e su ffered sh ip w reck in th e h an d s of a n y o th er m an th a n H y a tt.
T h e w h ole te ch n iq u e of cellu lo id w as th en d ev elo p e d p a in s ta k in g ly b y him , in all its endless d etails. S p e cial m a ch in ery w as in v e n te d , new m eth o d s w ere co n ceived . A ll th is is sho w n b y th e num erous su b seq u en t H y a t t p a te n ts.
I t is an a xio m th a t th e te s t of a v a lu a b le in v e n tio n is th a t it sh o u ld be in frin g ed , or a tta c k e d b y th o se w hose th in k in g cells are p a ssiv e u n til som e in v e n to r arouses th e m o u t of th e ir m e n ta l drow siness.
H y a tt, in his p a te n t su its, h ad p le n ty of exp erience of th e kin d . F o r tu n a te ly , his fin an cial b a ck e rs co u ld afford to d efe n d his rig h ts in th e a b su rd e d ly lo n g and e x p e n siv e p a te n t litig a tio n , w hich is a p ro v e rb ia l ch a ra cte ristic o f th e inefficient a d m in istratio n of th e p a te n t la w s of th is c o u n try .
I b elieve it w as G eo rg e W estin g h o u se w ho rem ind ed us th a t e v e r y su ccessfu l in v e n tio n passes th ro u g h th ree
Feb., 19x4 “ T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 9 i
stages: T h e first, w h en it is said : “ S u ch a th in g is absurd or im p o s sib le .” T h e second sta g e , a fte r th e p a te n t d escrip tio n s h a v e b ecom e p u b lic, and h a v e g iv en others th e m eans to im ita te and t r y to f i n d , loop h oles in th e p a te n t claim s, begin s w h en it is sa id : “ T h e th in g is n o t n e w .” A n d fin a lly , a fte r th e usefuln ess of th e in v e n tio n h as b ecom e so o b vio u s and th e d etails conn ected th e re w ith h a v e p e n e tra te d th ro u g h th e h ard skulls of th e lag g a rd s , th e n it sounds: “ T h e re is no in ven tio n a t a ll.”
L a w y e rs are g re a t in th is gam e. H y a t t ’ s in v e n tio n w en t th ro u g h e v e r y one o f th ese th ree sta g e s an d w ere it n ot for th e P e rk in M e d al, m a n y of us m ig h t h a v e fo rgo tte n th a t th e re e v e r w as such a m an as H y a tt, and th a t th e re w as a tim e w h en cellu lo id did n o t exist, or in v o lv e d v e r y d ifficu lt p roblem s.
H is p a te n ts w ere assailed on th e gro u n d th a t o th ers before him h a d u sed so lv e n ts a n d cam p h o r in co n ju n ctio n w ith n itro cellu lo se , b u t it w as stu d io u s ly o m itted th a t his p redecessors h a d used th ese in g re dients u n der e n tire ly d ifferen t co n d itio n s, for e n tire ly d ifferent pu rpo ses, and co u ld n o t p ro d u ce in t h a t w a y , H y a t t ’s v a lu a b le te ch n ica l effect. T h e v e r y so lv en ts w hich p ro v e d a b ar to a n y im p o rta n t a p p licatio n s for m olded p la stics, H y a t t did a w a y w ith , w h en he co n ceived his th e rm o p la stic m ass.
Som e of th e e a r ly d ra w b a c k s in th e te ch n ica l a p p lic a tions of H y a t t ’s d is c o v e ry w ere none oth er th a n ch em ical exp erts w ith w h ich h is fin a n cia l b a ck e rs su rro u n d ed him . H y a t t k n e w no c h e m istry , b u t he k n e w w ell ob served fa c ts in tim a te ly co n n ecte d w ith th e d etails of th e w o rk he h a d u n d e rtak e n . H is k n o w le d g e of n itrocellu lose w as o b ta in e d p iece-m eal b y his ow n exp erim en tin g. F a c ts fo u n d in b o o k s he acce p te d on ly a fte r he h a d ve rified th e m . I t so h a p p en e d t h a t he fre q u e n tly n o ticed th a t p rin te d s ta te m e n ts did not agree w ith his ow n o b se rva tio n s. One of th e ch em ical e x p erts in s is te d th a t “ cellu lo se w as cellu lo se ,”
regardless o f th e so u rce of s u p p ly , p ro v id e d it w as su fficien tly p u rified , an d t h a t n itro cellu lo se m ade from a n y k in d o f p u re cellulo se h a d th e sam e p rop erties.
H y a tt kn e w b e tte r w h en he fo u n d th a t th e article
T H E C O M P O S IT IO N O F P A IN T V A P O R S B y H e n r y A. G a r d n e r 1
R eceiv ed D ecem b er 18, 1913
F re sh ly p a in te d su rfaces g iv e to th e su rro u n d in g air a p e cu liar odor. In closed room s, th is odor is p ro nounced. Its n a u se a tin g effects are w ell kn ow n . P ain ters are in th e h a b it o f s ta tin g th a t th e v a p o rs of fresh p a in t h a v e a “ le a d y sm e ll.” T h is is p ro b a b ly due to th e fa c t th a t w h ite lea d is used as th e base upon w hich th e m a jo rity of p a in ts are p rep ared . T h e p a in ter has th e re fo re a lw a y s asso ciated th is p ig m e n t w ith th e ch ara cte ristic odor of fresh p a in t. Som e cases of ill
ness am o n g p a in ters h a v e been ascrib e d to th e effe cts of p a in t va p o rs. P e o p le o c c u p y in g fre s h ly d e co rate d sleeping room s w h ich are n o t w ell v e n tila te d , h a v e a t
1 A ssistan t D irecto r, T h e In s titu te of In d u s tria l R esearch, W ashington, D. C.
m ad e fro m ram ie, th e stro n ge st an d m ost ex p en siv e cellu lo se, w as in c o m p a ra b ly sup erior to th a t o b ta in e d fro m ch eap co tto n or ch eap p u lp cellulose.
Som e ch em ical e x p erts also m ad e th e p o sitiv e sta te m e n t to his b ack ers, th a t his p rocess w o u ld s u re ly lea d to te rrific exp lo sio n b ecau se he w as h e a tin g in a h o t press n o th in g less th a n g u n c o tto n , w h ich w as k n o w n to be a v io le n t ex p lo sive. T h o u g h H y a t t sta te d th a t he h a d b een usin g his process for q u ite a tim e an d still w as a liv e , it w as o b je c te d th a t th is w as sim p ly due to sheer go od lu c k w h ich w ou ld cease a t som e tim e ; if e v er it h a p p en e d th a t b y a ccid e n t or carelessness, th e h e a t in his presses rose a little h igh er, a v io le n t exp lo sion w as b o u n d to o ccu r, an d th is w ou ld be th e end o f th e cellu lo id in d u s try . T h e s e a rg u m en ts w ere n ot b y a n y m eans w ith o u t lo gic. A t t h a t tim e , it i s ' d o u b tfu l w h eth er a n y ch e m ist w h o k n e w th e ch em ical p ro p erties o f n itro cellu lo se w o u ld n o t h a v e th o u g h t it th e h e ig h t of fo lly to h e a t th is su b sta n ce u n d e r p ressu re .
H y a t t n o t b ein g a ch em ist, p refe rred to t r y a n d see fo r h im self w h a t w o u ld occu r. H e to o k a go o d -sized b lo ck of cellu lo id and h e a te d it in th e h y d ra u lic press a t a te m p e ra tu re fa r su p erio r to th e r e la tiv e ly low te m p e ra tu re s he w as u sin g in p ra ctic e . H e te lls me th a t he w as su fficien tly im p ressed b y a ll th e th r e a te n in g t a lk of th e ch em ical e x p e rts to screen him self fro m th e press b y m eans o f se v e ra l th ick n esses of cross b o ard s b eh in d w h ich he cou ld peep on an d see w h a t w as go in g to occu r. A ft e r th e te m p e ra tu re rose to th e p o in t w hen th e cellu lo id b egan to be d estro y ed , th e b lo ck sta rte d sizzlin g on a cc o u n t of th e em ission o f gaseo u s p ro d u cts. B u t he co n tin u ed th e ex p erim e n t u n til he m ade su re th a t n o th in g w orse o ccu rred th a n to sp o il th e m aterial.
T h e pessim istic ch em ical e x p e rts h a d fa ile d to ta k e in to co n sid e ratio n th a t th e in tro d u c tio n of su ch a large p ro p o rtio n of cam p h o r h a d p ro fo u n d ly m odified th e p ro p erties of n itro cellu lo se . T h e y h a d also o v e r lo o k e d th e fa c t th a t so lu b le n itro cellu lo se is n o t n i
tr a te d so m u ch as th e m ore ex p lo sive h igh er n itra te d c o tto n .
L . H. Ba e k e l a n d
tim e s co m p la in ed of illn ess fro m th e sam e cause. E . C . B a ly 1 exam in ed s p e c tro sco p ic a lly th e v a p o rs fro m b asic c a rb o n a te -w h ite lea d p a in t, and fo u n d e v id en ces of m e tallic le a d th e re in . T h e v a p o rs fro m b asic su lfa te- w h ite lea d p a in t or zin c oxid e p a in t, w h en exam in ed in a sim ilar m ann er, sh o w ed th e absence of m etallic co n s titu e n ts. Som e cases of lead p o ison in g am o n g p a in ters c o u ld be a scrib e d to th e v a p o rs fro m b asic c arb o n a te - w h ite lead p a in ts, if le a d co m p o u n d s co u ld a c t u a lly b e fo u n d p rese n t in such va p o rs. A rm stro n g and K le in ,2 a fte r co n d u ctin g an ela b o ra te series o f te sts, co n clu d ed t h a t lea d is n o t p resen t in th e v a p o rs fro m w h ite lea d p a in t, b u t t h a t th e to x ic effe cts p ro d u ced b y su ch v a p o rs are due alm o st e n tire ly to th e v o la tile s u b sta n ce s g iv en off b y th e tu rp e n tin e present.
1 The Oil and Colour Trades Journal, M ay 6 , 1911, p 1518 s J . S . C. 32, 320 (1913).
ORIGINAL PAPERS
9 2 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y V o l. 6, N o. 2 T h e w riter has m ade a series o f te sts w h ich confirm
th o se o f A rm stro n g and K le in , in so far as th e ir resu lts are con cern ed w ith th e n o n -m etallic c o n s titu tio n of p a in t v a p o rs. T h e w r ite r ’s te sts, h o w e ver, sh o w th a t th e v a p o rs fro m p a in t a p p a r e n tly c o n tain carbo n m on oxide, th e p oisonous n a tu re of w hich is to o w ell k n o w n to b e co m m en ted upon. T h e a m o u n t o f carbo n m onoxide e v o lv e d is also sho w n to be d ire c tly in flu en ced b y th e ty p e o f p ig m en ts used in th e p a in t. T h e defin ite presence o f a ld e h y d e s an d o rg a n ic a cid su b sta n ces in p a in t v a p o rs has also b een e stab lish ed b y th e se te sts.
T h e d a ta p rese n ted h as b ro u g h t fo rth co n sid e rab le in fo rm a tio n rega rd in g th e p h eno m eno n of o x id atio n as ap p lied to linseed oil an d linseed oil p a in ts. T h e resu lts are g iv e n w ith a 'v ie w to a w a k e n in g fu rth e r re search w o rk o f a sim ilar n atu re. A n o u tlin e of th e te sts m ade is h e re w ith p resen ted , to g e th e r w ith a su m m a ry o f th e re su lts o b ta in e d and in som e in stan ces a discu ssion o f th e d a ta . M a n y of th e te sts o u tlin ed w ere m ade in d u p licate .
E X P E R I M E N T I.— Four cylinders each 30 in. long and 9 in. in diameter, were formed of galvanized sheet iron. One end of each cylinder was fitted w ith a removable lid. The other end was closed. The scams were all soldered. The tanks were numbered from 1 to 4. The interiors of the tanks were brush- coated with raw linseed oil, soya bean oil, tung oil, and men
haden oil, respectively. T h e tanks were weighed previous to and subsequent to the application of the oil, in order to determine the am ount of oil applied. T h e tanks were individually con
nected up to a train of three W oulff bottles, the first of which contained 66° sulfuric acid, the second and third containing a saturated solution of barium hydrate. Vacuum was applied
common to each tank. The discolored sulfuric acid from each test had an acrid odor. The bottles containing barium car
bonate had an odor suggestive of aldehydes.
r e s u l t s : These tests indicate th at the phenomenon of
oxygen absorption which takes place when oils are spread in thin layers and exposed to the air, is accompanied b y the evolution of considerable amounts of organic substances. Large quantities of carbon dioxide are simultaneously evolved.
E X P E R I M E N T II.— A series of paints was prepared from those opaque white pigments which are most w idely used in the man
ufacture of exterior and interior paints (basic carbonate-white lead, basic sulfate-white lead, zinc oxide, and lithopone). The oil used was raw linseed oil. N o turpentine or drier was added.
The lead pigments were ground to a thick paste with 10 per cent of oil. The zinc pigments were ground to a paste with 15 per cent of oil. Oil in the proportion of about 7 gals, to the cwt.
of paste was then added to each paint, the quantity of oil added in each instance being sufficient to make paints containing approxim ately 60 per cent pigment and 40 per cent oil. E ach of the four iron cylinders described in Experim ent I was then cleaned and painted on the inside with one of the four paints.
An effort was made to spread the same am ount of paint in each tank. A fter painting, the tops were placed upon the tanks and they were connected up to W oulff bottles containing various reagents as shown in Fig. I. Uniform vacuum was applied to the end of each apparatus, and a 48-hour run was made. The air passing into the apparatus was scrubbed through a 10 per cent solution of caustic soda and then passed over soda lime in order to remove the carbonic acid present. The glass tubes coming from the ends of the cans were bent as shown in the illustration, to hold back any particles of paint which might be carried over, although such occurrence seemed highly improb
able and such precautions unnecessary. A part of each exit tube was heated with the flame of a Bunsen burner, in order to
Fi g. I — Ap p a r a t u s f o r De t e r m i n i n g Ch a r a c t e r o f Va p o r s f r o m Pa i n t e d Su r f a c e s
1— S o lu tio n K O H , 10 p e r c en t 2— S o d a Lim e
3— M e ta l C y lin d er P a in te d on In sid e -to the end bottle. T he air entering the tank was scrubbed
through a 10 per cent solution of caustic soda, and then passed .over soda lime to eliminate carbon dioxide.
Soon after the tests were started, the sulfuric acid in the first bottle of each train became discolored. W ithin an hour the acid had assumed an amber color. T h e barium hydrate contained in the other bottles became opaque within a short time. A t the end of a 2-day run, the sulfuric acid was dark red, and the barium hydrate solutions contained a dense white precipitate which proved to be barium carbonate. E ach series of apparatus was disconnected and the coatings on the interior
•of the tanks examined. T he amount of air passing through the tanks in 2 days was evidently insufficient to' complete the oxidation of the oils which under normal conditions would have been quite dry in th at time. The linseed oil was very soft and tacky. T he soya bean oil was but slightly oxidized. The fish oil was somewhat tacky, but it had dried to a greater extent than the other two oils mentioned. The tung oil was very hard and dry. The smell emanating from the tanks was most unpleasant, being somewhat characteristic in each instance of the type of oil used. A certain nauseous smell, however, was
4— H e ate d G lass T u b e 5— S u lfu ric A cid 6 6 ° 6 , 7— B ariu m H y d ra te S olution
break up, if possible, any organic form of lead or zinc, which m ight be present in the vapors, since certain organic compounds of lead m ay not respond to tests for lead as made with ordinary reagents.
In every test the sulfuric acid contained in the bottle next to the tank was turned amber color w ithin 5 minutes after the beginning of the test, thus showing th at the drying paints were giving off considerable organic m atter. A fter a 48-hour run, the acid in each bottle was dark red. The amount of carbon dioxide evolved in each test was considerable. N o quantitative determ ination of carbon dioxide was made in any case. A t the end of the experiment, the cans were re-weighed to determine the am ount of oxygen absorbed. T o the w riter’s surprise, there was recorded a loss of weight in one test, and but slight, if any, gains in the other tests. The basic carbonate-white lead paint lost 2 per cent b y weight. The basic sulfate-white lead paint and the zinc oxide paint neither gained nor lost, the weight of the films remaining constant. T he lithopone paint showed less than 1 per cent gain.
T h e bottles containing the sulfuric acid were removed from each train and the contents examined. Upon dilution with water.
Feb., 1914 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 93 the acid in the bottle, through which the fumes from the drying
basic carbonate-white lead paint had been passed, became opaque. I t was a t first thought th at this cloudiness of the diluted acid might be due to the presence of lead sulfate, formed by the absorption of volatile lead compounds eliminated b y the drying paint. Alcohol was added to a portion of the liquid.
It immediately became clear, thus indicating the absence of lead. A very thorough examination of the liquid was then made, and not a trace of lead was found. The sulfuric acid through which the vapors from the other paints were passed, w as also examined. N o metallic compounds were found. The exper
iments were repeated, the only refinement being th at of intro
ducing in front of the sulfuric acid bottles in the trains con
nected to the lead-painted cylinders, a bottle containing strips of filter paper saturated with sodium sulfide solution. The papers were not darkened in either case, thus giving further indication of the absence of lead compounds. In another experiment, one of the cylinders was painted with basic car
bonate-white lead paint and the gases evolved were passed through a heated tube, finally being drawn through a 2 per cent solution of nitric acid. The test was run for forty-eight hours.
The acid was evaporated on a steam bath. The residue was taken up with dilute acetic acid and a few drops of water. It
lead paints each required about 100 cc. permanganate solution.
The acids in the trains connected to the cylinders painted with zinc paints required from 19 to 39 cc. of permanganate, that connected to the lithopone cylinder requiring the least amount.
The solutions of acid thus oxidized were transferred to separatory flasks and shaken with ether. T h e ether solutions were thor
oughly washed with w ater and then evaporated. In each instance a dark substance which had the appearance of heavy oil was left as a residue. This substance was found to be soluble in alcohol, in which solvent very acid reactions were given.
N o attem pt was made to identify the acids present. Their complex nature would m ake such determination rather difficult, especially when working on small quantities.
r e s u l t s : 1 . The above experiments indicate th at the
vapors from drying paints contain acids of a water-soluble nature.
These acids apparently contain formic acid. The amount of such acid evolved m ay be influenced b y the typ e of pigment present in the paint. The basic pigments are apparently more active than the neutral or inert pigments.
2. Organic acids of a fa tty or arom atic nature are apparently evolved from drying paints. T h e am ount evolved m ay bear some direct relation to the pigment present in the paints. The basic pigments apparently are most active in this respect.
was tested microscopically1 for lead after the addition of copper acetate and potassium nitrate. N o response for lead was shown in the test.
r e s u l t s : The results of these tests indicate th at drying paints, containing zinc or lead pigments, do not em it volatile compounds of a metallic character.
When spread as thin films, oil-pigment paints are capable of evolving considerable amounts of organic substances without showing any material increase in their respective weights.
E X P E R I M E N T II I,— Experim ent II was repeated after cleaning the interior of the tanks and applying fresh coats of paint.
The first W oulff bottle in each train contained distilled water.
The second bottle contained 66° sulfuric acid. A fter a 48-hour run, the contents of the first bottle in each train were examined. T he w ater in each instance was acid in reaction.
There were required for neutralization from 1 cc. to 14 cc. of iV/io K O H . The w ater in the bottle connected to the cylinder painted with lithopone showed the lowest am ount of acid, while the water connected to the cylinder painted with basic carbonate- white lead showed the largest percentage of acid. The presence of carbon dioxide in the w ater m ay partially account for the acidity of these tests. A portion of the neutralized acid was tested qualitatively for the presence of aldehydes. Small amounts of aldehydes were found present. Form ates were also found present. The sulfuric acid in each of the four bottles was diluted with w ater and titrated w ith N /10 potassium permangan
ate to determine the am ount of reducing substances present. The acids in the trains connected to the cylinders painted with white
1 P ag e 167, " L e a d P oisoning a n d L ead A b so rp tio n ,” Legge a n d G oadby.
L ongm ans, G reen & C o.. Pub lish ers.
T h e a ld e h y d ic re d u cin g su b sta n ces an d th e acid s w h ich are e v o lv e d fro m p a in ts are, no d o u b t, resp o n sible fo r th e odors w hich are co in cid e n t to th e d ry in g of p a in ts. 'I n th e w r ite r ’s op inion , h o w e ve r, th e re are also e v o lv e d su b sta n ces o f a m ore poisono u s n atu re.
In a sm u ch as large p e rce n ta g e s o f carb o n d io xid e are form ed , it is a t lea st p o ssible th a t carb o n m on oxid e m a y also b e p ro d u ced . T h e fo llo w in g ex p erim e n ts w ere d esigned to d ete rm in e w h eth er th is g a s is re a lly fo rm ed
E X P E R I M E N T IV .— A fter m any attem pts to devise a suitable apparatus in w'hich to determine the percentage of carbon dioxide or carbon monoxide which m ight be evolved b y drying paints, the apparatus shown in Fig. I I was found to be most satisfactory for the purpose. T h e first experiment made with this apparatus was conducted upon raw linseed oil. The in
teriors of two carefully weighed glass bottles, each having a capacity of one gallon, were coated w ith linseed oil. The oil was poured into each bottle and allowed to flow over the entire area of the interior, this being accomplished b y revolving the * bottle. A fter draining out the superfluous oil, the bottles were re-weighed to determine the amount of oil used for the test.
Cork stoppers carrying glass air-tubes, were then inserted.
The stoppers were thickly coated w ith paraffin to make them air-tight. The apparatus was connected up as shown in Fig. II. Vacuum was applied a t one end. A s the purpose of the experiment was to determine the presence and am ount of carbon dioxide or carbon monoxide in the vapors from the oil, the air entering the bottles was first freed of its content of carbon dioxide and carbon monoxide. This was accomplished b y first F ig . I I —A p p a r a t u s f o r D e t e r m i n a t i o n o f C O2 a n d CO i n V a p o r s f r o m P a i n t e d S u r f a c e s
1— S o lu tio n K O H , 10 p e r c e n t 6,7— B o ttle s P a in te d on In sid e
2, 14— Io d ic acid in tu b e ; S o y a Oil B a th 3, 4, 15, 16— 1 p e r c e n t K I S o lution 5— S o d a Lim e
8— F u m in g S u lfu ric Acid 9— D istilled W a te r
10—13, 17, 18— B ariu m H y d ra te S o lu tio n
94 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y V o l. 6, No. 2 scrubbing it through a solution of caustic soda in order to remove
the carbon dioxide. The air was then run through a U-tube containing iodine pentoxide heated in a bath of soya oil to 150°
C. a t which temperature carbon monoxide is oxidized to carbon dioxide.1 .The iodine liberated was absorbed in a 1 per cent solution of potassium iodide and the carbon dioxide formed was taken up b y the caustic soda and soda lime in the subsequent train of apparatus.
A fter the tests had been running for 15 minutes, the fuming sulfuric acid in bottle 8 was turned amber color, showing that organic substances evolved b y the oil were being absorbed.
The absorption of these organic vapors b y the sulfuric acid pre
vented such vapors from interfering w ith the subsequent train of liquids in which the percentage of carbon dioxide and carbon monoxide were to be determined. B ottle 10 containing saturated barium hydrate, the strength of which was determined b y titra
tion, showed a slight precipitate of barium carbonate a t the
• end of the first 10-minute run. A t the end of a 5-liour run, bottles 10 -11 and 12 showed quite a noticeable deposit of barium carbonate. B ottle 15, containing potassium iodide, did not change color until the tests had been under w ay for over an hour.
A t th a t period the reagent became slightly yellow, showing th at some iodine had been carried over into this bottle, thus indicating the presence of carbon monoxide in the vapor. The barium hydrate in bottle 17 a t the same time became cloudy, showing th at traces of carbon monoxide which had been evolved, had been oxidized and absorbed as carbon dioxide. The percentage of carbon monoxide evolved b y the drying oil in five hours was determined b y titrating the barium hydrate contained in bottles 10 to 13 with N /10 oxalic acid, using phenolphthalein as an indi
cator. The titration was made direct. T h e amount of carbon dioxide found present was 0.016 per cent. T h e amount of carbon monoxide was not measurable, although it was shown to be present in traces.
r e s u l t s : T his experiment indicates th at linseed oil in drying gives off traces of carbon monoxide.
E X P E R I M E N T V .— Experim ent IV was repeated, coating the interior of the bottles in this case w ith basic carbonate-white lead paint in place of raw linseed oil. T he test was run for five hours. The am ount of carbon dioxide produced in th at time was 0.0305 per cent. The carbon monoxide evolved amounted to 0.006 per cent. The experiment was made w ith basic sulfate- white lead paint in place of basic carbonate-white lead. The experiment was accidentally interrupted.
T he experiment was again repeated, using zinc oxide paint in place of the white lead paint. The amount of carbon dioxide evolved was 0.0292 per cent. The am ount of carbon monoxide evolved was 0.0039 P e r cent.
The experiment was again repeated, using lithopone paint in place of the zinc oxide paint. The am ount of carbon dioxide evolved was 0.022 per cent. A mere trace of carbon monoxide was found.
Experim ent V was repeated w ith a basic carbonate-white lead paint. The first bottle leading from the painted bottles con
tained fuming sulfuric acid to intercept and collect the organic vapors. The second bottle contained water. The third bottle contained alkaline bisulfite solution to collect any traces of aldehydes which, if evolved b y the paint, m ight possibly escape absorption b y the sulfuric acid. The fourth and fifth bottles contained w ater and caustic soda solutions, respectively, the latter to collect the carbon dioxide or phenols evolved. The vapors passing from the last bottle were passed through a U-tube containing small lumps of caustic potash. The U-tube was immersed in hot soya oil. A t the end of a 5 -hour test, the U-tube was removed from the hot oil and the lumps of caustic potash removed and examined for the presence of formates which,
1 " M e th o d Used for E x a m in a tio n of T u n n e l G a s,” b y D r. A. Sydell, H y g ien ic L a b o ra to ry , W ash in g to n , D . C.
if present, would indicate th at absorption of carbon monoxide had occurred. A fter dissolving the potassium hydrate in water, m aking acid w ith tartaric acid and distilling over barium car
bonate suspended in water, the filtrate from the barium carbon
ate was treated w ith a small percentage of bichloride of mercury.
A fter the solution had stood over night, a very faint precipitate of calomel was observed, indicating the presence of carbon monoxide.
r e s u l t s: These experiments would tend to show th at the
highly basic pigments stim ulate the evolution of organic sub
stances from linseed oil paints, especially influencing the amount of carbon dioxide and carbon monoxide evolved.
T h e a m o u n t o f air e n terin g th e p a in te d b o ttle in a 5-hour run w as in su fficien t to cau se a n y m a rk ed o x id a tio n . T h is ex p la in s w h y such sm all a m o u n ts of carbo n d ioxid e an d carb o n m o n oxid e w ere o b ta in e d . T h e e x tre m e ly sm all q u a n titie s p rese n t m ade th e a n a ly tic a l d e te rm in atio n s a m a tte r of g re a t care. T e s ts e x te n d in g o v e r a g re a te r p erio d sh o u ld b e m ade, in ord er to s u b s ta n tia te th e figu res p rese n ted . T h e w rite r is d esig n in g a n o th e r ty p e o f a p p a ra tu s in w hich it is h op ed m ore a cc u ra te d ete rm in atio n s m a y be m ade.
E X P E R I M E N T V I.— In this experiment a portion of lithopone paint was reduced with 15 per cent of turpentine and then applied to the interior of the bottles. A t the end of three hours, the percentage of carbon dioxide evolved was 0.04, while the per
centage of carbon monoxide was 0.003. This result m ay be due to the oxidation of the turpentine.
r e s u l t s: Turpentine apparently accelerates the reactions
which are responsible for the formation of volatile products from drying oils. The oxidative properties of the turpentine are probably responsible for this result.
G E N E R A L D IS C U S S IO N OP R E S U L T S
T h e resu lts o b ta in e d in E x p e rim e n t I I , in w h ich th e p a in t film s sh o w ed b u t slig h t if a n y in crease of w eig h t a t th e end of th e te sts, are in te re stin g. T h e y m a y be p a r tia lly acco u n te d for b y assu m in g th a t th e a m o u n t o f air passed th ro u g h th e ta n k s in 48 hou rs w as v e r y sm all. I t w ill be w ell a t th is p o in t to d iscuss th e e x p erim en ts on linseed oil and o il-p ig m e n t p a in ts, as m ad e b y S a b in .1 H e describes a series of te s ts in w h ich v a rio u s p a in ts w ere a p p lied to sm all glass p la tes, th e in crease in w e ig h t sho w n b y th e p a in ts b ein g r e cord ed a t d ifferen t periods. A t th e en d o f 7 d a y s, raw linseed oil sh o w ed a gain in w e ig h t o f 18 per cen t, w h ile w h ite lea d p a in t sh o w ed a gain o f a p p ro x im a te ly 15 per cen t.
T h e w riter carrie d o u t a sim ilar series .of te sts w ith a se t of p a in ts m ade up w ith 60 per cen t o f p ig m e n t and 40 p er cen t of raw linseed oil. T h e gain in w e ig h t of th e film s a t th e en d of 7 d a y s w as as fo llo w s:
P e r c en t L inseed o il... 1 4 .0 C o rro d ed w h ite le a d ... 6 .4 Su b lim ed w h ite le a d ... 7.1 Zinc o x id e ... 1 ... 5 .4
L ith o p o n e ... 5 .9
T h ese te sts in d ic a te th a t o il-p ig m e n t p a in ts do not ga in in w e ig h t to th e sam e e x te n t as ra w linseed oil.
H e re to fo re, h o w e ver, in v e s tig a to rs h a v e n o t g iv e n co n sid eratio n to th e p o s sib ility th a t p ig m en ts m a y s tim u la te n o t o n ly th o se processes w h ich cau se th e oil to increase in w eig h t th ro u g h th e a b so rp tio n of o x y g e n ,
1 Th i s Jo u r n a l, 3 , S 4 .
Feb., 1914 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 95 bu t also th o se processes and re a ctio n s w h ich cause th e
oil to elim in ate v o la tile su b sta n ces, w h ich m ig h t d e
tra ct m a te ria lly fro m th e w eig h t o f th e p a in t. In th is connection it is of in te re st to cite th e te s ts of O lsen and R a tn e r1 upon th e d ry in g of linseed oil. T h e y reco rd a gain in w eig h t of 1 8 .p er cen t a t th e end o f a p p ro x i
m ately 10 w eeks. T h e y also sh o w ed th e elim in a tio n of a p p ro x im a te ly 5 per ce n t o f carbo n d ioxid e and 15 per cen t of w ater.
S U M M A R Y O F C O N C L U S IO N S
I. W hen linseed oil or sim ilar d ry in g oils are spread in th in la y e rs, th e ab so rp tio n of o x y g e n w h ich ta k e s place is acco m p an ied b y th e e v o lu tio n of co n sid erable am ounts of carb o n d ioxid e and o rgan ic su b stan ces.
C arbon m on oxide is also e v o lv e d in sm all am o u n t.
II. Oil p a in ts co n ta in in g lea d or zin c p ig m en ts do not em it v o la tile co m p o u n d s of a m e tallic n atu re.
I I I . D ry in g p a in ts e v o lv e w ater-so lu b le a cid su b stan ces such as fo rm ic acid , as w ell as a cid su b sta n ces which are a p p a re n tly o f a f a t t y n atu re. C arb o n d i
oxide and carb o n m on oxid e are also p rese n t in th e v a pors from th e d ry in g p a in t. T h e ty p e o f p ig m e n t used in th e p a in t m a y d ire c tly affect th e a m o u n t and c h a r
acter of th e v o la tile su b sta n ces prod u ced . B a sic pigm ents a p p a re n tly stim u la te th e e v o lu tio n of such products.
IV . A ld e h y d ic su b sta n ces are p resen t in th e v a p o rs from d ry in g oil p a in ts. T h e s e su b sta n ces p ro b a b ly h ave a m arked b a c te ric id a l e ffe ct upon p a th o g e n ic b acteria and w o u ld th u s a cc o u n t for th e s a n ita r y valu e ascribed to o il-p ig m e n t p ain ts.
T h e w riter d esires to th a n k H . C . F u lle r, L . G . C ar- m ick and th e sta ff of T h e In s titu te o f In d u stria l R e search for th e ir assistan ce in c a rry in g o u t th e a b o v e exp erim ents.
In s t i t u t e o f In d u s t r i a l Re s e a r c h Wa s h i n g t o n
M E T A L L O G R A P H Y A S > P P L I E D T O IN S P E C T IO N
B y W i r t T a s s i n R eceiv ed D ecem b er 11, 1913
T h e su d d en fa ilu re of en gin eerin g stru c tu re s o f m etal, the s ta tic p h y sic a l te sts of w h ich , b efore use, p o in te d to th e good q u a lity o f th e m a terials, is w ell kn ow n . Such failu res h a v e tisu a lly b een a ttr ib u te d to a so- called d e te rio ra tio n k n o w n as “ fa tig u e .”
W h e th er or n o t re p e a te d stresses b elo w th e ela stic lim it of th e m etal can set up such a d e te rio ra tio n m a y be q u estion ed . O ne fa c t h as h o w e v e r been p ro v e n b e yond all qu estio n , and th a t is t h a t in a n y m etal th e re are alw ays p rese n t ce rta in s tr u c tu ra l co n d itio n s, th e in fluence of w h ich are e ith er fa v o r a b le or u n fa v o ra b le to “ fa tig u e .”
T h e c h a ra cte r of th e se s tr u c tu ra l co n d itio n s is in d i
cated in p a rt o n ly, and th e n o ften b y ch an ce, b y th e static and d y n a m ic te sts. I t m a y , h o w e ve r, b e co m p letely re v e a le d b y m e ta llo g ra p h ic m eth o d s, t h a t is, b y the stu d y o f th e s tru c tu re o f th e m etal as seen on th e etched su rface u n der th e m icroscop e.
T h e po ssibilities of m e ta llo g ra p h ic m eth o d s as an additional sa feg u ard to d eterm in e q u a lity h a v e been
1 J . S . C. / . , 31, 937 (1912).
reco gn ized , b u t th e ir usefuln ess h as been lim ite d b y th e la c k o f p r o ta b ility in th e a p p lia n ces n e ce ssa ry for th e ir use. T h is has m ade it d ifficu lt, if n o t im p ossible, to s tu d y th e fo rgin g , th e ca stin g or th e b ar as a w hole, w ith th e resu lt t h a t th e m e tallo g ra p h ic field h as been lim ited to th e e x a m in a tio n of m ore or less sm all sp e ci
m ens c u t from th e piece and w h ich , lik e th e b a r u sed for th e m ach in e te sts, m a y or m a y n o t be re p re se n ta tiv e o f th e w hole.
I t is th e p u rp o se of th is p a p e r to d escrib e a co m p lete m e tallo g ra p h ic o u tfit w h ich is p o rta b le and m a y be used eith er in th e m ill or th e la b o r a to ry and is se rv ic e able for th e s tu d y of th e fo rgin g , th e b a r or th e ca stin g as a w h o le; t o g iv e ce rta in ty p e s o f stru c tu re fo u n d in th e ferro u s m e tals; to g iv e a list of certain p ro b ab le causes for fa ilu re an d to o u tlin e a sch em e fo r th e ir d e
te ctio n an d th u s su p p le m e n t o th er m eth o d s of te stin g .
T H E A P P A R A T U S
T h e a p p a ra tu s1 con sists of a m icroscop e, illu m in a tin g d e v ice and a cam e ra, all self-co n tain ed , F ig . i , A , B and C.
T h e m icroscop e, F ig . 2, con sists o f a b arre l, b, an d a d ra w -tu b e , d, m o u n ted on a h a n d le arm p ro v id e d w ith a coarse and a fine a d ju stm e n t. A tta c h e d to th e b arrel is a sh o u ld er, c, w h ich h o ld s a rod, r, co n tro lled b y a set screw . T h e base o 'f-th is rod rests on th e pinion h ead o f th e h a n d le-a rm an d w hen lo ck e d w ith th e s e t
screw p re v e n ts th e coarse a d ju s tm e n t from o v e rru n nin g w h en u sin g th e cam e ra. T h e w h ole is carried on a b ase w h ich is th e sta g e . T h ro u g h th e cen ter of th e sta g e is a i-in c h circu lar op en in g w h ich affords free sp ace fo r th e o b je c tiv e w hen ex a m in in g large m asses b elo w it. L e v e lin g screw s are p ro v id e d , one in each of th e fo u r corn ers of th e sta g e , w h ich p e rm it th e a d ju s tm e n t of th e m icroscop e p e rp en d icu lar to n e a rly a n y su rface.
T h e illu m in a tin g d ev ice con sists of an arm , a, in F ig . 2, w h ich lo ck s in to th e m icroscop e b arre l b y m eans of a th re a d e d co llar. T h e arm serves to c a rry th e co n d en sin g a rran ge m e n t m ade up of a te le sco p e tu b e , tt, w hich carries th e lenses. T h e tu b e is m o u n ted in a slee ve, y, p ro v id e d w ith a set-screw to lo c k it in a n y p o sition . A h a n g er, h, fro m th e arm is a tta c h e d to th is slee ve b y m eans of a tru n n io n co n tro lled b y a set-screw w h ich p e rm its th e tu b e as a w h ole to be tilte d a t a n y angle. A v e rtic a l a d ju s tm e n t is p ro v id e d fo r b y a set-screw a t th e o u te r e x tr e m ity o f th e arm . T h e rear o f th e te le sco p e tu b e carries a sh ield , xx, p ro v id e d w ith clips to hold th e sou rce of lig h t w hen e le c tr ic ity is used and is slo tte d to h o ld a ro d and a m o v a b le lam p carrier w h en gas is used.
T h e sou rce of lig h t m a y b e an a ce ty le n e je t or an e le c tric lam p .
W h en a ce ty le n e is used th e gas m a y be o b ta in e d fro m a ge n e ra to r or fro m a p re sto lite ta n k . T h e s u p p o rt for th e lam p is a ro d w hich lo c k s in to th e slo t in th e sh ield of th e illu m in a to r. On th e rod is p lace d th e m o v a b le carrie r fo r th e sou rce o f lig h t, see B , F ig . 1.
W h en e le c tr ic ity is used th e la m p is carried in a so c k e t fixed in an in su la te d m etal h oo d an d h eld in
1 M a n u fa c tu re d b y B ausch an d L om b, R o ch ester, N . Y .
9 6 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y V o l. 6, N o. 2
F i g . 1 — C
of a r e a d y ch an ge o f o b je c tiv e s w ith o u t an un screw in g m otio n and con sists of a cla m p o p erate d b y a sp rin g co n tro lled b y tw o hand les. P ressin g th e h an d les opens th e clam p and p e rm its th e in sertio n o f a ring, one of w hich is p ro v id e d for each o b je c tiv e and to w h ich it h as b een p re v io u s ly fasten ed .
T h e cam e ra, see F ig . 1, is co n n ecte d w ith th e b arrel of th e m icroscop e b y a tu b e w h ich slips in and o u t like th e d ra w tu b e of th e m icroscop e an d m a y be re m o v e d w ith th e sam e ease. T h e cam e ra m oves w ith , and b eco m es p a rt o f th e b arrel and a n y d egree o f fo cu sin g is possible. T h e d ista n ce b etw e en th e e y e piece and th e gro u n d glass is a co n s ta n t so th a t th e a m p lifica tio n is sta n d a rd for each m a gn ifica tio n . T o use th e cam era th e d ra w tu b e of th e m icroscop e is re m o v e d and th e tu b e o f th e cam e ra inserted .
Verf/ca/ ///um/ner&r
to
Z
One 16 an d one 4 c. p. carb o n fo r a 6 v o lt, 4 c. p.
tu n gste n .
A n y o f th ese can d le p o w er tu n g ste n lam p s m a y be u sed b u t th e one reco m m en d ed is th e 6 v o lt, 16 c. p.
lam p k n o w n as “ H e a d lig h t M a z d a , N o . 68, 12 G ., c a n d e la b ra b a s e .”
T o g e t th e lig h t fro m th e co n d en sin g tra in th ro u g h th e o b je c tiv e use is m ade of a d e v ice k n o w n as a “ v e rtic a l illu m in a to r ,” K in F ig 2. T h is d e v ice screw s in to th e b arre l of th e m icroscop e b elo w th e h a n g er w h ich carries th e co n d en sin g tra in . T u rn in g th e p la te d o f th e illu m in a to r to som e d esired an g le reflects th e illu m i
n a tin g r a y , w h ich en ters th e a p e rtu re , dow n upon th e su rface of th e m e tal. T h is in tu rn reflects th e lig h t up th ro u g h th e b arrel to th e eye.
A “ q u ic k -a c tin g nose p ie c e ” is fitte d to th e low er en d of th e v e rtic a l illu m in a to r. T h is d e v ice p e rm its
T h e a p p a ra tu s len d s itse lf re a d ily to a ll fo rm s of m e ta llo g ra p h ic w o rk and is a d a p te d to th e needs of th e in sp ecto r, th e en gin eer of te sts and th e m e ta l
lu rg ist. I t m a y b e used in th e m ill or th e la b o r a to ry an d is e q u a lly a d a p te d for th e s tu d y of th e m ass, F igs.
4, 5 an d 6, or th e sm all sp ecim en. I t is used b o th for v isu a l e x a m in a tio n s and fo r m a k in g p h o to g ra p h ic record s. I t is p o rta b le , self-co n tain ed an d co m p a ct.
M E T A L L O G R A P H IC M E T H O D S
s a m p l i n g.— B y sa m p lin g is m ean t th e lo c a tio n and n u m b er o f areas to be p o lish ed . I t is n o t n ecessa ry nor p ra ctic a b le to polish th e en tire su rface of th e m ass p ro v id e d th a t a su fficien t n u m ber o f sm all areas be ta k e n w h ich sh all p ro p e rly rep rese n t it. In sele ctin g th e se areas it is d esirab le to fo llo w som e fixed ru le and a lw a y s p rep are th e su rfa ce a t d efin ite p o sitio n s w hich sh all b e th e sam e for th e sam e k in d of o b je c ts so as to be of v a lu e fo r com p ariso n. T h is is e sp e cia lly d e
sirab le w h en gra in size is to b e ta k e n in to co n sid eratio n as th e gra in m a y v a r y g r e a tly in d ifferen t p a rts of th e w o rk as fro m th e th ic k to th e th in p a rts of a castin g .
F ig . 1— A F i g . 1— B
p o sitio n w ith referen ce to th e lenses of th e condensin g tra in b y clip s fa ste n e d to th e shield of th e illu m in a to r;
see A , F ig . 1.
T h e cu rre n t m a y be o b ta in e d fro m an a ccu m u la to r or b y c u ttin g d ow n th e lig h tin g cu rren t. A la m p b an k to red u ce a n o v o lt cu rren t is w ired as in F ig . 3. T h e la m p resistan ce need ed for th e v a rio u s can d le po w er 6 v o lt tu n g ste n m in ia tu re lam p s is:
T w o 32 and one 16 c. p. carbo n lam p s fo r a 6 v o lt, 16 c. p. tu n g ste n m in iatu re.
One 32 and one 8 c. p. carb o n fo r a 6 v o lt, 8 c. p.
lam p .
One 32, or tw o 16, an d one 4 c. p. carb o n lam p s for a 6 v o lt, 6 c. p. tu n g ste n m in iatu re.
Feb., 19x4 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
97
In b illets th e cross sectio n a t each en d sh o u ld be tak en , to g e th e r w ith se v e ral areas p a rallel to th e d ire c
tion of th e w o rk an d p re fe ra b ly on tw o or m ore sides.
W ith rounds p rep are a cross sectio n a t each end and several oth ers p a rallel to th e d ire ctio n o f th e w o rk.
W ith flats ta k e a lo n g th e ce n te r lines of th e several sides. W ith h o llo w fo rgin gs and sim ilar m a terial areas alo ng th e o u ter and inn er su rfaces in th e d irectio n of th e w o rk sh o u ld be chosen to g e th e r w ith tw o or m ore cross sectio ns a t each end. W ith castin g s b o th th ic k and th in p a rts sh o u ld be sele cted and w here th e cope and d rag can b e d istin gu ish e d , sectio n s a lo n g each should be ta k e n to g e th e r w ith areas in th o se p a rts w hich h a v e to ta k e th e m a jo r p a rt o f a n y sudden load , as tru nn ion s.
Sections sh o u ld n e ve r be p rep ared to o n ear a n y d istorted p a rt as a sh eared ed ge or p u n ch ed hole.
W ith ann ealed m a terial, e sp e cia lly w ith castin g s w here the so ak in g h as been p ro lo n ge d , care sh ould be ta k e n to get b elow th a t p a r t d eca rb o n ize d b y th e a ctio n of the flame»
c l e a n i n g.— A ft e r p o lish in g an d before e tch in g clean th e su rface w ith co tto n m oistened w ith alco h o l or gasolin e.
e t c h i n g.— A fte r clean in g, th e su rfa ce is n ow r e a d y to h a v e its s tru c tu re d ev elo p e d . T h is is u s u a lly done b y m eans of som e re a g e n t w h ich a tta c k s or colors som e c o n s titu e n t of th e m etal m ore th a n it does o th ers.
F o r th e ferro u s m etals a 10 per cen t so lu tio n of p icric acid in 95 per cen t alco h o l w ill be fo u n d th e m ore useful. S o ak som e a b so rb e n t c o tto n in th e so lu tion . T a k e up th e co tto n w ith a p a ir o f to n g s or tw e e ze rs and a llo w th e excess a cid to d rain off. P la ce th e co tto n on th e su rface to be e tch e d and m o ve it b a c k an d fo rth till th e desired d ep th of e tch is o b ta in e d . T h e degree of te m p e ra tu re a f f e c t s t h e sp eed o f e tch in g , th e colder it is th e lon ger th e tim e; w ith 55 to 70 degrees f of te m p e ra tu re a b o u t 20 secon ds is su fficien t.
A fte r etch in g w ipe off th e a cid w ith co tto n or clean , s o ft w a ste, th e n clean th o ro u g h ly w ith c o tto n m ois
te n ed w ith alcoh o l.
C are m u st be ta k e n th a t th e etch in g fluid c o ve rs th e
Fi g. 4 Fi g. 5
T h e size of th e sectio n s po lish ed sh o u ld be a b o u t three inches w ide b y a b o u t tw e lv e inch es long.
p o l i s h i n g.— T h is is done b y w heels and b u ffs d riven b y an e lectric or a p n e u m a tic grin d er, one or th e o th er of w hich is u s u a lly to be fo u n d in a n y m ill. W hen p reparing a su rface th e fo llo w in g tr e a tm e n t h as b een found s a tis fa c to ry for m ost p u rp o ses: If th e su rface is ve ry ro u gh grin d d ow n w ith a 24 gra in em e ry w heel, follow w ith a c lo th w heel ch arge d w ith 60 em e ry , th e n use a sim ilar w heel ch arge d w ith 120 em e ry , fo llo w w ith a b u ff ch arge d w ith w ash ed flour em e ry p a ste and finish w ith a b u ff ch arge d w ith rouge.
T h e a b o v e p ro ced u re requ ires a b o u t 15 m inu tes to finish an area 3 inch es b y 12 in ch es an d w ill g iv e a su r
face th a t is p e rfe c tly s a tis fa c to ry if th e etch in g is done with p icric a cid or iod ine. I t is n o t n ecessa ry t h a t th e surface sh o u ld be free fro m scra tch e s b u t it is n ecessary that th e scra tch e s sh o u ld all lie in th e sam e d irectio n .
F ig . 6
w h ole a re a and th a t th e sa tu ra te d c o tto n is m o ved b a c k and fo rth w ith a r a p id ity su fficien t to insure th e ev en d istrib u tio n of th e a cid o v er th e su rface a t all tim es as o th erw ise th e re m a y b e v a ria tio n s in th e c h a r
a cte r o f th e e tch w h ich m a y g iv e rise to fa lse co n clu sions. T h is v a ria tio n in th e etch is less lik e ly to h ap p en w ith picric acid th a n w ith o th e r etch in g m edium s.
t h e v i s u a l e x a m i n a t i o n.— W ith th e u n aid ed eye
lo o k fo r strea k s or areas w h ich are d iffe re n tly colored . C arb o n -rich areas w ill u su a lly a p p e ar d a rk e r an d car- b on-lean areas lig h te r th a n th e re st o f th e su rface. In g en eral th e seg regatio n s of th e a llo y elem en ts w ill also be in d ica te d b y a color d ifferen ce. H e a t and fo rgin g cra ck s are co m m o n ly rend ered visib le as w ell as pip es, seam s, sh akes, flow lines, co ld sh u ts, w elds, etc.
W h en m a k in g th e m icro sco p ic e x a m in a tio n th e in stru m e n t sh o u ld b e le v e le d , if n ecessa ry, b y m eans of th e screw s on th e sta g e .
