The Journal of industrial and Engineering Ghemlstry
Published b y T H E AM ERICAN CHEMICAL S O C IE T Y
A T B A S T O N . P A .
Volume VI S E PT E M B E R , 1914 No. 9
BOARD OF EDITORS E d ito r : M . C . Wh i t a k e r A s s is t a n t E d ito r : Le o l a E . Ma r r s
A s s o c ia te E d ito r s : G. P. A d a m so n , E. G. B ailey , H. E „ Barnard, G. E . B a rto n, A . V . Bleininger, W m , Blu m , Wm. B r a d y , C . A . Browne, F . K . Ca m eron, W m . Ca m pbell , P. B. Ca rpenter, C . E . Ca spari, V . C o b le n tz , W. C. Geer, W . F . Hillebrand, W . D . Horne, T . K am o i, A . D . L it tle , C . E . Lucke, P . C . M c l l h i n e y , J. M. M a t t h e w s , T . J. Pa rk er, J. D. Pen nock, Clifford Richardson, W . D . R ich ar dson, G. C . Stone, E. Tw it chell, R . W a h l, W . H. W alk er, W . R . W h itn e y , A . M . W rig ht.
P u b lish ed m o n th ly . S u b sc rip tio n price to non-m em bers of th e A m erican C hem ical Society, $6.00 y early . F oreign p o stag e, seventy-five cents, C an ad a, C u b a a n d M exico excepted.
E n te re d as Second-class M a tt e r D ecem b er 19, 1908, a t th e Post-O ffice a t E a sto n , P a ., u n d e r th e A c t of M a rc h 3, 1879.
Contributions should be addressed to M. C. Whitaker, Columbia University, New York City
Communications concerning advertisem ents should be sent to The American Chemical Society, 4 2 West 39th St., New York City Subscriptions and claim s for lost copies should be referred to Charles L. Parsons, Box 505, Washington, D. C.
Es c h b 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 T E N T S
Mon treal Me e t in g Po s t p o n e d... 706
Or iginal Pa p e r s: S yn th etic C elite and L arg e C ry sta ls of T ricalcic Silicate. B y E d w a rd D . C a m p b e ll... 706
H yp othetical C om bin ation s in W a te r A n alysis. B y R . B . D o le ... 710
C hem istry of th e B leach in g of C o tto n C lo th . B y John C . H e b d en ... 714
T h e C h em istry of P in e Oil. B y M axim ilian T o c h . . . . 720
Oils of the C oniferae. I— T h e L ea f and T w ig O ils of C ub an and L o n gleaf Pines and the C one O il of Long- leaf Pine. B y A . W . S ch o rg er... 723
T he Specific H e a t of C aliforn ia Petroleum s. B y H arold E . W a le s ... 727
D eterm ination of S ilve r and B ase M eta l in Precious M eta l B ullion. B y F rederic P . D e w e y ... 728
T he E ffect of B read W rap p in g on th e C hem ical C om p o sition of the Lo af. B y H . E . B arn ard and H . E . B ish o p ... 736
Some D a ta on P e a n u t B u tter. B y C . A . A . U t t ... 746
T h e Influence of S u lfur on Soil A c id ity . B y H . C la y L in t ... 747
T he F erric A lu m E stim ation of C aseine. B y H . V . A m y and H . H . S ch ae fe r... 748
Studies in S yn th e tic D ru g A n alysis: I I — E stim ation of A n tip y rin . B y W . O. E m ery and S. P a lk in 751 T h e D eterm in ation of M ercu ric Iodide in T ab lets. B y A . W . B e n d e r... 753
La b o r a t o r y a n d Pl a n t: T he D evelop m en t of th e R o ta ry K iln and Its A p p lica tion to V arious C hem ical and M etallu rg ica l Processes. B y R ich a rd K . M e a d e ... 754
A C om bin ation W a te r Softener and Storage T an k . B y L . M . B o o t h ... 76 °
A N ew Seal for the P revention of A eration in D eaerated Liquids. B y F ra n k B a c lim a n n ... 764
Addresses : Shoddy and C arbonized W aste. B y Louis Joseph M a t o s ... 765
Chem ical Engineering. B y C harles S. P a lm e r... 768
Ch an dler Fo u n d a t io n Le c t u r e: Som e A sp ects of In d ustrial C h em istry. B y L . H . B a e k e la n d ... 769
Cu r r e n t In d u s t r ia l Ne w s: Am m onium Chloride, a N ew B y-p ro d u ct of G as W orks, e tc ... 778
S tockholm G as-W orks in 1 9 1 3 ... 779
C arbon M onoxid e and N itric O xide from H eatin g and L igh tin g B u rn ers...- ... 779
Oil in A u stra lia ... 779
C an adian C o a l... 779
B ritish C oal E x p o rts in th e F irs t H alf of 1 9 1 4 ... 779
T h e A ltio r Process of D ie -C a s tin g ... 779
A N e w B earin g M e t a l... 780
English T rad e U nions in 1 9 1 2 ... 780
A u tom atic E q uip m en t for P lacin g Pow ders in B o ttles on N e t W eig h t B a s is... 780
D ecreased A c tiv it y in English S h ip b u ild in g ... 781
A m erican R a ilro ad s... 781
Steam Pow er U sed for G eneration of E lectric C u rren t in P ru ssia ... 781
Diesel Engines in the Italian N a v y ... 781
Calcium C arbide, C yan am id e and N it r a te ... 781
M in eral-W ater Prod uction in 19 1 2 ... 781
No t e s a n d Co r r e s p o n d e n c e: O b ituary— R ussell S. P en n im an ... 782
T h e S ta b ility of R esin A cid s a t S lig h tly E lev a ted T em peratures— A C o rrectio n ... 782
E xh ibitio n M in e a t the P an am a-P acific Exposition . . . 782
Ind ustrial A ccid en ts in P en n sylvan ia in 19 1 2 ... 783
Pe r s o n a l No t e s... 783
Go v e r n m e n t Pu b l ic a t io n s... 784
Bo o k Re v i e w s: A T ex tb o o k of T herm odyn am ics; In dustrial O rganic A n alysis; D ie Ind ustrie der C y an - verbindungen, ihre E n tw ick elu n g und ihre gegenw aer- tiger S tan d (T h e In d u stry of th e C yan o gen C o m pounds, I ts D evelopm en t and Its Present C on dition ); T h e C h em istry of C a ttle F eeding and D a iry in g 787 Ne w Pu b l ic a t io n s... 789
j R e c e n t I n v e n t i o n s ... 79° i M a r k e t R e p o r t ... 792
7o6 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 . 9
MONTREAL MELTING POSTPONED
T h e p o stp o ne m e n t of t h e M o n tre a l M e e tin g , j u s t an n o un ced b y the officers of th e S o ciety , will be a great d is a p p o in tm e nt to t h e m a n y chemists who h a v e been looking fo rwar d to this e v e n t w it h keen a n t ic ip a tion and pleasure. M a n y h a v e sca rc ely realized the far-rea ching effects of the w ar in E u rope, while the seriousness of t h e sit uatio n is pressing h e a v il y and in an ever-increasing v a r i e t y of forms upon other members of our profession.
C on dit io n s in C a n a d a which necessitated the p o s t
pon em en t m a y be best c o n v e y e d b y the follo wing letter to S ecretary Parsons from Prof. R. F . R u t t a n , C h a ir m a n of the M o n tre a l C o m m it te e :
De a r Dr. Pa r s o n s:
T h e declaration of w a r betw een G erm an y and E n glan d found me a t M etis B each , 500 m iles dow n the S t. Law rence, p la yin g golf w ith a feeling of relief th a t our organization for the m eeting w as so com plete.
W e had a m eeting of all th e E x e cu tiv e C om m ittee in tow n this afternoon, and w ith profound regret, fu lly realizing w h a t it m eant to yo u and the S ociety, decided th a t th e m eeting could n o t be m ade a success in B ritish te rrito ry this autu m n . I w ired y o u a t once as follow s:
“ C an a d a is sending the first con tin gen t of 20,000 v e r y soon a n d a second and th ird w ill follow.
" M o n tre a le rs feel th a t w e are a t w a r w ith G erm an y and A u stria, and are b eh avin g as if th e enem y w ere th reaten in g us.
“ T h e H arbor, canals, etc., are under M a rtia l L aw . T h e excursions w ere off,_ as the com p an y canceled ou r co n tra ct for the steam ers for the rapids and harbor.
" N o G erm an m em ber of the S o c iety w ould n atu ra lly com e to B ritish soil and all w ith G erm an nam es w ould be questioned a t the boun d ary. M a n y are even now turned back. W e felt th a t th e exclusion of so m an y prom inent m em bers of the S o ciety w as a high price to p a y for a m eeting here.
" A n y foreigners w ould be su bjected to disagreeable form alities an d conditions on com ing here ju s t now.
" I t w ould be im possible to a ttr a c t to th e C on ven tio n the sligh test p u blic interest in M on treal, outside a few dozen chem ists. N o one w ould com e to the C onversazione or th e garden parties we h a d arranged, and w hile there w ould su rely be the feeling of good fellow ship am ong ourselves, it w ould be over
shadow ed b y th e trag ic w ar w e are in a t present. ”
It is sad to look over the wreck of our hopes of a big and successful meeting. Everything was organized and under way
ORIGINAL
SYNTHETIC CELITE AND LARGE CRYSTALS OF TRICALCIC SILICATE
By Ed w a r d D. Ca m p b e l l
R eceived J u n e 26, 1914
“ T o r n e b o h m and Le Ch a te lie r as early as 1897 described ‘ a l i t e ’ as the crystalline material sep ar ati ng o u t fr om an inter -crystalline m a g m a ‘ celite.’ T o r n e b o h m 1 further la ys stress on the fa c t t h a t celite is fusible a t the ordinar y clinkering te m perature and promotes the cr ysta ll izati on of the alite. N o claim
* Tonin-Justrie Z„ 21 (1897), 1148.
even to rehearsing for the Smoker. The toastmaster and speakers for the banquet, the chemical and other scientific "stunts” for the Conversazione were arranged and the hall for the exhibits prepared, which, by the way, would have been of exceptional interest. We feel very sad about it all today I assure you.
The Principal and Vice-Principal (of McGill University) and Sir Wm. Osier, who had promised to speak at the banquet, are in Europe, as well as many of our staff. Their return is uncertain. Everything was against the meeting and only our desire to give you the hand of good fellowship and the advanced state of the preparations made us hesitate at all about calling everything off.
I hope you appreciate our situation and that we have your sympathy.
I came up this morning feeling sure the meeting would go, but have been convinced it could not be made more than an apology for a convention, which it would be a waste of time to attend.
When things settle down again we shall once more extend you an invitation, and hope you will do us the honor of accepting it.
I am, with kindest regards.
Sincerely yours,
(Signed) R . F. Ru t t a n
T h e officers of the S o c ie ty ac te d p r o m p tly upon the a d v ic e of the co m m itte e and issued notice of in
definite p o stp o nem en t of t h e A n n u a l M e e t i n g of 1914.
I t now seems im probable t h a t a n y me eting of the S o c i e ty will be held this fall.
T h e question of transferring the c onventio n to an
other place was considered b u t in v i e w of the tre
mendous influence of ev e n ts now pe ndin g and the im p o r ta n t duties which will d e v o lv e upon the chemical profession, alike in neutral a n d in in v o l v e d countries, it was t h e alm ost unanim ou s opinion of the officers of the S o c i e ty t h a t it will be impossible to arrange for a successful m eetin g early in t h e fall and t h a t business con ditions t h r o u g h o u t the c o u n tr y render it improb
able t h a t it w ou ld be ad v is ab le to h a v e a meeting later in t h e year. T h is la tt er point, how ev er , will be defi
n it e ly decided later and a n y notice t h a t .m a y become necessary will appear in the O cto b er or November journals.
W e believe the decision of the officers will be unani
m ously ap p ro v e d b y the mem ber sh ip of the Society.
PAPERS
is made t h a t alite is a definite chem ical or mineralogical e n t i t y and it is ac co rding to this interpretation of th e term s t h a t t h e y are used in this article.”
In the work done la st y e a r 1 discs of well burned clinker, m ade from the r a w m aterial fr om one of the lea ding c em ent mills in t h e L eh igh V a l l e y , were placed betw een discs of pure m a gn esiu m oxide, M g O , and the pile so co nstr ucted hea ted to va rious tempera
tures rangin g from 1 4 7 5 0 to 1 5 7 5 ° C . T h e portion of t h e clinker c o n sti tutin g t h e celite as defined by
1 Th i s Jo u r n a l, S , 6 2 7 .
Sept., 1 9 1 4 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 70 7
Tôrnebohm and Le Ch ate lie r and a m o un tin g to from twenty (20) to t w e n t y - s e v e n (27) per cent of the weight of the clinker was liquefied and absorbed b y the magnesium oxide, M g O , discs. F ro m analyses of the discs satu ra te d with celite t h e pe rcentag e co m p o sition of this la tte r and its molecular ratios could be calculated. T h e results are given in the following table :
Ta b l e I
T em p era- P e r P ercen tag e com position Experi- tu re T im e c e n t «•--- *--- *
ment ° C. H rs. celite SiOs AlsOs FejO j C aO M gO
Ai... 1475 13 2 0 .8 7 11.21 19.28 8 .3 0 5 5 .8 9 5 .3 2 11.22 19.36 8 .3 7 5 5 .7 3 5.31 Aj... 1510 3 2 1 .4 0 13.63 18.24 7 .9 9 5 5 .2 0 4 .9 5 13.64 18.11 7 .9 4 5 5 .3 6 4 .9 6 Ai... 1575 2»/j 2 6 .2 5 14.46 17.3 6 8 .1 2 55.91 4 .1 5 14.39 17.34 8 .2 2 55.91 4 .1 5 B<... 1575 8 2 0 .8 0 9 .1 3 19.89 8 .8 7 5 9 .1 8 2 .9 2 9 .0 7 19.8 6 8 .9 9 5 9 .1 5 2 .9 3 The molecular ratios of the celite ca lcula te d from the means of the analyses in T a b l e I and reduced to the basis of one hund red (100) molecules of R 20 3- (AI2O3 + Fe2 03) are giv e n in T a b le II.
Ta b i.i: I I — Ra t i o s i n Ck l i t b Ab s o r b e d
100 R jO j
Experiment AlaOj FctO i SiOi C aO M gO R O
Ai... 7 8 .4 2 1 .6 77.1 413 5 4 .6 5 46 7 .6 5 Ai... 7 8.1 2 1 .9 9 9 .3 4 3 3 .5 5 3 .9 48 7 .4 A... 7 6 .9 2 3.1 108.2 4 5 1 .5 4 6 .5 4 9 8 .0 Bi... 7 7 .7 2 2 .3 5 8 .9 4 2 6 .5 2 9 .0 45 5 .5 It has seem ed be tter t o ca lc ula te the molecular ratios given in T a b l e I I to a basis of 100 molecules of R 20 3, ( A 120 3 + F e 20 3) in stead of to a basis of 100 molecules of AI2O3 alone, on ac c o u n t of some of the conclusions which were draw n la st year and which were as follows: (1) “ T h a t a lth o u gh th e proportion of ferric oxide, F e 20 3, to the alumina, A 120 3, is a little higher in the celite th a n in the alite, t h e difference is not v e r y m a rk ed and the assu m ptio n t h a t the ferric oxide is m olecularly eq u iv a le n t to al um in a so far as the formation of celite goes seems justifiable alth ou gh the hydraulic properties of the al um in ates and ferrites differ in degree.” (2) “ W it h a giv e n b a sic ity of the mass as a whole the pr oportion of silica to alumina and ferric oxide in the celite increases w ith the te m p e r a
ture.” (3) “ W it h a g iv e n tempe rature, the proportion of silica to th e alum in a and ferric oxide in the celite decreases as t h e ba s ic ity of th e mass as a whole in creases.”
The hypothesis was also a d v a n c e d at t h a t time,
“ That alite consists essentially of a calcium aluminate fusible at a little a b o v e 1400° and capab le of dissolving, when liquid, calc ium orthosilicate and calcium oxide, this latter bein g the more readily soluble, and t h a t the solubilities of the orthosilicate and calcium oxide follow laws parallel to thos e which govern the solu
bilities of salts in liquid solution. N o evidence is yet forthcoming t o enable t h e chem ical con stitution of the pure fusible al um in ate to be giv e n so t h a t no ch em ical formula is su ggeste d for i t . ”
The experimental w ork described in t h e present paper
"’as carried on under the a u t h o r ’s direction b y R . A.
Price and H. Y . T a n g . T h e o b je c t of this work was to obtain p e rfectly fluid materials of the same molecular ratios as the celites ob tained last y e a r and th u s obt ain experimental evidenc e which should test t'he correct
ness of the proposed h y p o th e s is .1
1 Th i s Jo u r n a l, 5 , 6 2 7 .
In order to reduce the problem to its simplest term s it was th o u g h t best to select materials as free as p r a c tic able from ferric oxide, Fe«0 3, and magn es ium oxide, M g O . T h e materials decided upon were a carefully washed kaolin, pure al um in um oxide, A 120 3, finely ground and washed q u artz sand and ch em ic all y pure ca lcium carbonate. Th ese materials th o r o u g h ly dried and a n alyzed were a c cu rately weighe d and mixed in the proportions of kaolin 400 grams, A 120 3 (pure) 4 7 0 grams, c. p . C a C O j 2 1 5 1 grams. T h e weighe d materials were placed in a porcelain jar mill and re
v o l ve d for three hours in order to insure uniform m ix ture. T h is base mixture was ca lc ula te d to giv e on fusion a material of the follow ing pe rce ntag e co m posi
tio n: Si0 2 9.1 7, A 120 3 3 0.9 1, F e 20 3 0.2 3, C a O 5 9.6 1, undetermined 0. 07 and molecular ratio, calculated to the basis of 1 00 molecules of R 20 3( A 120 3 + F e 20 3):
A 120 j 9 9.5 4, F e 20 3 0.4 6, S i0 2 5 0, C a O 3 5 0, which re
duced to its low est term s would g iv e an empirical formula of 2R2O3.SiO2.7CaO. B y using this “ C ” mixture and ad ding pure silica, S i0 2, and calcium carbonate, C a C O s , th e ratio of silica and calcium oxide to alumina could be easily m ade the same as t h a t fo u nd to exist in a n y of the celites recovered from ce m ent clinker.1
I t wras found b y experience t h a t it was necessary to use a large p la ti nu m crucible in order to retain the fluid celite. T h e crucible used was a fl a t-b o tto m e d cylindrical one 47 X 50 mm. and c a pable of holding ab ou t 100 grams of the raw mixture so t h a t the weight of material after fusion was in the neighborho od of 60 grams.
T h e fusions were effected in a furna ce su bs ta n tia lly the same as the one described in our pr evious article, the tem peratures bein g controlled and measured b y th e same me thod s t h a t were e m p l o ye d in our former experiments. If an oxidizing atm osph ere is m a in tained in the furnace the deterioration of the th erm al couple is not great, am o un tin g in the present case to on ly one (1) per cent after t w o y e a r s ’ use. T h e a c co m p a n yin g te m perature readings h a v e been corrected for this change. T h e dense vitreo us mass fo u n d in the b o t t o m of the crucible after each fusion could be rem oved on ly b y shatterin g w ith a steel chisel an d t a p p in g the outside to loosen t h e pieces fr om the pla tinum.
Fusions were made of the “ C ” mixture alone and also of a mixture ma de b y ad ding, in a c cu rately weighed amounts, pure silica, SiO*, and pure calcium carbonate, C a C 0 3, to the “ C ” mixture in such pro
portions t h a t t h e molecular ratios were th e same as those fo und b y analysis of t h e A 3 celite ( T a b le II ), th e only difference being t h a t in the Ci celite th e R 20 3 was prac ti ca ll y all A 120 3 and the R O all C a O . Th is would g iv e for the C i celite the follow ing perce ntage composition: S i0 2 13.74, A 120 3 23.35, F e 20 3 0.17, C a O 62.74. T h e molecular ratio w ould then be 99.54 A I2O 3, 0.46 F e 20 3, 99.3 S i0 2, 487-4 C a O .
In preparing the C i fusions the raw m ixture was placed in the p la tin u m crucible and the furnace hea ted over nig ht b y an ordinary Ridker, the tem per at ure
1 Th i s Jo u r n a l, 5 , 6 2 7 .
reaching over 1 1 5 0 ° b y morning, when the M6ker blast was p u t on and the temperature raised to well ab ove the fusion point, 1 5 8 5 1 5 9 0 ° , at which tem p era
ture it was held for from 2—3 hours; when it was judged th at the solution was co mplete the temperature was g rad ually lowered, from 4~6 hours being required to bring the tempe ratu re down to ab ou t 1 4 1 5 ° , after which the burner was turned out and the openings in the furnace closed and the whole allowed to cool over night.
1 he fusions of the C mixture alone were not cooled b y g r ad u all y lowering the temperature bu t merely b y closing up the furnace and letting it cool. T h a t this m et ho d of slow cooling between the highest temperature of fusion and 1 4 1 5 0 produced well defined crystals is shown b y the slightly magnified photograph of a section of one of the pieces of C , C celite in Pla te I.
7° 8 T H E J O U R N A L O F I N D U S T R I A L
principle was used as t h a t em pl oyed in the removal of celite as described in a former paper.1 Four weighed discs of pure magnesium oxide, MgO, were placed in the furnace and the temperature raised over night to a little over u o o ° C. Three weighed pieces of the C id celite were placed in a pure magnesium oxide, M g O , dish made b y cu tting down a crucible.
A N D E N G I N E E R I N G C H E M I S T R Y Vo l. 6, No. 9
T R IC A L C IC S IL IC A T E C R Y STA LS
A s the sections of Q C and C ,d celites showed them to contain large well-developed crystals imbedded in the solvent in which t h e y had formed the next step w-as to remove this latter in order to recover the crystals in as pure a condition as possible. T o effect the re
m ov al of the fusible solvent from the crystals the same
Pl a t e I I I
C . eight hours after the melting point of the solvent had been passed. T h e furnace was then closed and allowed to cool over night. On removing the dish and discs t h e y were found to be firmly c e m e n t e d
together b y the absorbed celite while the residue in
1 T h i s J o u r n a l , 5, 627.
Pl a t e I
T h e crystals of the C jd celite which was the most slowly cooled from the m axim um temperature were even larger th an those of C i C celite.
T o s t u d y the hydraulic properties some of the C b celite and C i C celite was ground to pass through a 200 mesh sieve. On mixing with water the material ta k es a flash initial set and takes its final set under a Gilmore needle in from i o - i 2 minutes. If after adding water enough for normal consistency the material is worked for 4 or 5 minutes under the spatula it be
comes slower setting, abou t 10 minutes being required for the initial set and 24 hours or more for the final.
Pa ts of the C i C and C b celites made b y working under the spatu la until the flash set was past were placed in coM water, after 24 hours’ standing in moist air and su bm itt ed to the usual 24 hour boiling test.
In both cases the pats g av e a perfect boiling test, there being no signs of warping or cracking, although t h e y were not quite as strong or hard as a good P o rt
land cement.
Pl a t e i r
T h e dish containing the pieces was placed in the hot furnace and the blast p u t on in order to raise the tem
perature a b o v e the melting point of the solvent in as short a time as possible. F o rty -f ive minutes after the dish was p u t in the furnace the temperature read 1470 C . and it was held within five degrees of 1465° C.
for three hours and then raised at the rate of 25° C.
per hour during a period of five hours, reaching 1590°
Sept., 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 É N G I N E E R I N G C H E M I S T R Y 709
the dish consisted of a mass of thin plate-like, inter
locking crystals from which the solvent had been al
most completely drained aw a y.
The three pieces of celite placed in the dish weighed 18.312 grams and t h e residue weighed 6.123 grams;
thus 66.56 per cent was absorbed and 33.44 per cent recovered as crystals. T h e crystals were broken apart and some of the best "ones selected for chemical analysis and determination of their optical properties.
, 1’i.a ti: xv
The appearance of the materials after the absorption is given in the a c co m p a nying photographs. Plate II is a side view showing the four magnesium oxide, MgO, discs with the magnesium oxide, M g O , dish at the top. Pl a te I I I is a to p vi ew of the dish showing the three masses of crystals in place. Plate I V shows the masses of crystals inverted to show better the crys-
1'I.ATK V
tal faces and Pla te V shows some of the individual crystals together with a centimeter scale graduated ia millimeters. I t will be noticed in this photograph that some of these crystals were nearly seven mini
s t e r s in length.
Analyses of selected crystals gave the following results:
SiOi AliOa CaO
Per cent Per cent Per cent
I 23.74 5.4 7 70.71
II* * I I I ... 23 .5 0 --- 70.78
Using the first analysis the molecular ratio calculated to the basis of one hundred molecules is 100 S i0 2, 13.6 AI2O3, 320.3 C a O . If we deduct from the total C aO enough to form tricalcic silicate the 20.3 molecules left to combine with the 13.6 AI2O3 is within the limits of experimental error which would be required for a calcium alumínate of the formula s C a O ^ A U O j . The specific g r av ity of a selected fragment of crystals determined b y means of T h o u le t’s solution gave 3.0 0 2.
The mass of crystals showed a light green color, due probably to a thin film of adhering solvent since many individual crystals were almost perfectly color
less. The crystals are pseudo-hexagonal and show no cleavage. T h e average refractive index is 1.70S and the birefringence is ve ry weak. T h e crystals are optically negative and appear biaxial. T h e optical axial angle 2E is exceeding small.
These results agree ve ry closely with those reported by F. E. W rig ht1 for the tricalcic silicate prepared by Shepherd and Rankin. His report reads as follows:
“ 3 C a 0 . S i 0 2( C a 0 7 3-5 9 . Si0 2 26.41)— This com pound, which is not stable at its melting point, but changes into a mixture of free lime and orthosilicate at higher temperatures, crystallizes in small equant grains, colorless and apparently with ou t cleavage.
The average refractive index is approximately 1.715, and the birefringence is ve ry weak, not over 0.005.
Interference figures are difficult to obtain because of the weak birefringence and the fineness of the grains, which rarely measure over 0.03 mm. diameter. I h e grains appear uniaxial or biaxial with small optic axial angle and are optically negative. On some of the preparations cut nearly normal to the optic axis, especially on those from preparations containing a little AI2O3, fine twinning lamellae were observed with low extinction angles indicating possibly t h a t the crystal system is monoclinic. T h e distinguishing optical features of this compound are eq uan t development, lack of cleavage, weak birefringence, optically negative character with 2E small or zero, and refractive index about 1.715. I t is an interesting fa c t t h a t in preparing this compound from the mixed oxides at^ 1400 or 1500o, the compounds, free lime and orthosilicate, are first formed and these in turn unite to form the tri
calcic silicate on longer heating.”
These results still further confirm the existence of tricalcic silicate first sta ted to be the essential con
stituent of alite b y Le Chatelier. T h e existence of this compound which had been questioned for some time received confirmatory evidence b y the work of A. H. White1 and still greater confirmation b y t h a t of Shepherd, Rankin and W rig ht above quoted.
T h e two upper pure magnesium oxide discs which were saturated with celite were ground up and the S i0 2,
1 T h i s J o c k k a i , , 3 , 2 1 1 . i Ib id ., i , 5 .
7 i o 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. 9
A 1j 0 3 and C a O determined in four gram samples b y su bsta ntia ll y the same m e th o d of analysis as t h a t e m p lo ye d in our pr evious work on the recovery of celite. T h e weights of the various constituen ts re
covered were as follows:
Sam ple SiO i AliOi FesOj CaO
A ... 0 .0 5 1 8 0.1 3 7 7 0 .0 0 3 6 0 .2 7 0 4 B ... 0 .0 5 1 5 0 .1 3 6 9 0.0038 0.2 6 9 4
T h e sum of these giv e the following perce ntage co m po si
tion:
SiOa AliOs l'V:Oi CaO
11 .1 7 2 9 .6 7 0 .7 9 58.3 7
C a lc u la tin g from this analysis the molecular ratios on the basis of 100 molecules of R 20 3 (A 120 3 + F e 20 3) we h a v e 98.3 A 120 3, 1.7 F e 20 3, 62.8 S i 0 2, 352.4 C a O . If we su b tra c t from th e to ta l C a O th e am o un t theo ret ic a ll y necessary to form tricalcic silicate there would be left 164 molecules of C a O to combine with 100 molecules of R»0 3. T h ese figures in dicate almost co nclusively t h a t the fusible alum ínate co nsti tutin g the solv ent in celite is the one described b y Shepherd, R a n k i n and W r ig h t h a v in g the formula s C a O ^ A ^ O s 1 and a m eltin g point of ab o u t 1390 o.
SU M M A R Y
T h e foregoing work confirms, in general, the h y pothesis “ T h a t celite consists essentially of a calcium alum inate, fusible a little a b o ve 14000 and capable of dissolving, when liquid, calcium orthosilicate and calcium oxide,” bu t we m a y now ad d t h a t the alum in at e has the formula 5 C a 0 . 3 A l 20 3 and t h a t if t h e concen
trati on of the calcium oxide, C a O , is sufficient and solu
tion complete, pure tricalcic silicate will crystallize ou t on slow cooling. T h is also suggests a new th e o retical fo rm ula for Por tland cement.
T he Le Chatelier formula first proposed was X ( 3 C a 0 , S i 0 2) + Y ( 3 C a 0 . A l 20 3). T h is called for the calcium oxide C a O , b y weight to equal 2.8SÍO2 + i . 6 A 120 j. T h is al w a y s gives in practice a large excess of free lime. T h e N e w b e r ry for mula X ( 3 C a 0 . S i 0 2) + Y ( 2 C a 0 . A l 20 3) calls for calcium oxide b y weight to equal 2 .8S i0 2 + i . i A 120 3 b u t still ca nnot be adhered to -in prac tice w ith o u t the cem ent carry ing excess free lime. T h e for mula which would be suggeste d b y t h e w ork ab o v e described would be X ( 3 C a 0 . S i 0 2) + Y í s C a O i p A l í O s ) which would call for calcium oxide b y w eig h t to equal 2.8Si02 4 - o.9 A 120 3. Such a formula would conform more closely with the results obtain ed in t h e best practice.
Ch e m i c a l La b o r a t o r y Un i v e r s i t y o f Mi c h i g a n
An n Ar b o r
H Y P O T H E T IC A L C O M B IN A T IO N S IN W A T E R A N A L Y S I S 2 B y R . B. Do l e5
IN T R O D U C T IO N
T h e procedures followed in determining the various mineral ingredients of nat ural waters h a v e become fairly well sta nd ardized , th e differences of opinion in
1 A m . J . S et., [55] 29 (1909), 293.
J T aper read before th e D ivision of W ater, Sewage, a n d S an ita tio n a t the 49th M eeting of th e A m erican C hem ical Society, C in cin n ati, A pril, 6-10, 1914. Pu b lish ed by perm ission of th e D irecto r. U n ited S ta te s Geological Survey.
1 C hem ist, U n ite d S ta te s Geological S u rv ey .
t h a t respect now being chiefly in regard to the accuracy with which determ inations should be made. The form of reporting the result is, however, still a fruitful source of incon ven ience and disagreement. The min
eral con stituents are vario usly reported in ionic form, in h y p o th e tic a l com bination, in oxide form, and in e qu iv ale n t of calcium carbonate. T h is divergence of practice makes it impossible to compare the work of t w o chemists w it h ou t definite knowledge of their me thods of c o m p uta tio n and laborious recalculation of their results. C o n sequ en tl y, an effort is being made to agree on a uniform manner of reporting results in connection with the formu latio n of standard methods for the analysis of water, now bein g conducted jointly b y co m m it tee s of the Am erica n Ch em ical Society, the A m er ican P u bli c Healt h Association, and the Association of Official Ag ric ultu ral Chemists. This paper discusses th e present confusing condition and the ad v a n ta g e s of reporting the ac tu al fac ts of analysis in ionic form.
F A C T V E R S U S O P IN IO N
A s ta te m e n t of an analysis in h yp o th e tic a l combina
tions is o b vio u sly a mixture of f a c t a n d opinion. The am ounts of iron, calcium, sulfate, and other radicles are determ ined b y various reactions; approximate separation of scaling from non-scaling constituents is effected b y t re a tm e n t w ith dilute alcohol; bu t further th a n this, ordinary chemical tests contribute little to kn ow le dge regarding the chemical composition of mineral waters, and co nsequently the e x a c t amounts of the different salts in solution are la rgely conjectural.
T h o u g h salts are p ro b a b ly present it is a mathematical im pos sibilit y co rrectly t o apportion t h e bases among t h e acids after h a v in g fo u nd on ly the amounts of the acids and bases present.
C O M M O N F O R M S O F C O M B IN A T IO N
A s this la c k of definite information gives free rein to the im agin atio n there are m a n y opinions as to how the bases and acids should be combined. Though each m ethod has ardent ad v o cates, each is a personal selection whose excellence can be prove d only by the or y. In order to show the essential practical differ
ences in schemes of co m binat ion and some of the con
fusion to which t h e y lead, the most com mon methods ha ve been applied to th e analysis of the water of Missouri R ive r shown in T a b l e I. Th is chemical composition is not at all exceptional, b u t it has been
Ta b l e I — An a l y s i s o f t h e Wa t e r o f Mi s s o u r i Ri v e r n e a r Ru e g g, M o . ( a ) — Re s u l t s i n Pa r t s Pe r Mi l l i o n
R esu lts of R eacting
Co n s t i t u e n t s a n a l y s i s v a l u e s
S i l i c a ( S i O i ) ... 2 9 . 0 I r o n ( F e ) ... 0 . 5 C a l c i u m ( C a ) ... 5 2 . 0 M a g n e s i u m ( M g ) ... 1 6 . 0 S o d i u m ( N a ) ... 3 1 . 0 P o t a s s i u m ( K ) ... 6 . 5 C a r b o n a t e r a d i c l e ( C O j ) . ; . *... . 0 . 0 B i c a r b o n a t e r a d i c l e ( H C O s ) '. ... 1 7 8 . 0 S u l f a t e r a d i c l e ( S O < ) ... 1 0 4 . 0 N i t r a t e r a d i c l e ( N O a ) ... 2 . 9 C h l o r i n e ( C l ) ... 1 2 . 0 D i s s o l v e d s o l i d s b y e v a p o r a t i o n 3 4 6 . 0 T o t a l r e a c t i n g v a l u e o f b a s i c r a d i c l e s ...
T o t a l r e a c t i n g v a l u e o f a c i d r a d i c l e s ...
E r r o r o f c l o s u r e o f r e a c t i n g v a l u e s ...
* ( a ) U . S . G e o l . S u r v e y , W ater-Supply PaPer 2 3 6 , 8 0 .
purpo se ly selected because it represents a large group of waters in which carbonate is sufficient to satisfy
0.0179 2.5948 1.3136 1.3454 0.1664 0.0000 2.9192 2.1632 0.0467 0.3384 5 !4381 5.4675 0.2 7 per cent
Sept., 191 4 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 7 1 1
either calcium or m agn es ium b u t insufficient to satisfy both.
The first a d v a n ta g e of sta tin g the actual facts of an analysis is seen b y observing the reacting values or combining equivalents, which ha v e been computed b y multiplying the a m o un t of each radicle b y its valence and dividing the produc t b y its molecular weight, for they indicate t h a t the proba ble error of this analysis is about 0.3 per cent. W h e n hy potheti ca l combina
tions are made, one of three procedures is usually followed:
(1) All the bases and acids ex cep t the alkalies present in appreciable am oun t are es ti m a te d and the excess of acid is computed to an eq u iv a le n t of sodium and po
tassium salts.
(2) All the bases and acids ex cep t carbonate are estimated and the excess of base co m p uted to an eq u iv alent of carbonates.
(3) All the bases and acids are determined and the figures representing the salts are “ doctored” to bulance.
These practices effectually conceal errors of technique and leave it entirely to the ju d g m e n t of the analyst whether his error of closure is reasonable, and the evidenceon which his ju d g m e n t is based is completely masked because his h yp o th e tic a l combinations show no error at all. On the other hand, the probable accuracy of the work can be calculated directly from the ionic s ta te m ent as in dicated in the table.
Silica has not been included am ong either acids or bases. Some w aters1 of unusual character m a y con
tain the silicate radicle, b u t it is safe to conclude that it is absent from most natural waters. Whether silica is a colloid depends on our definition of colloid, but whatever it m a y be called it does not usually enter into the system of reac tive bases and acids. This conclu
sion was reached several years ago b y Kahlenberg and Lincoln,2 and K o h lr a u sc h 3 and others make practically the same state m en t. A m o n g 8,000 analyses of surface waters from all parts of the Unite d States the writer finds that if silicate is not included the acid radicles are in excess in 40 per cent and the basic radicles in 60 per cent of the analyses and t h a t the difference either way am ounts to on ly 1 or 2 parts per million, bears no m ath em at ic al relation to the qu an tity or the proportion of silica, and m a y as reasonably be ex
plained b y error of analysis as in a n y other way. This digression is inserted because it has been proposed to the committee to include rules for com puting silica to silicates of the various bases.
Table II gives h yp o th e tic a l combinations of the analytical d a t a in T a b l e I. All the sets of combin a
tions represent schemes used either b y a large number of analysts or b y one or t w o concerns t h a t examine many samples fr.om all parts of the country. T h e list might be much more extensive. N o extreme, but mathematically correct, schemes t h a t are unused ha\ e been introduced, and the table has been further simplified b y o m itt in g all b u t the more commonly - measured constituents. T h e on ly difference between Columns 1 and 2 is t h a t sodium nitrate is calculated in
•Clarke. F. W .. U . S. Geol. Survey, Bull. 491 (1911). 183.
'■Jour. Phys. Chem.. 2 (1898), 77.
' Z- physik. Chem.. 12 (1893). 773.
Si02... 29
FetOa... 1*c(H C 0 3)«... 'i.6 C a(H C 03)i... 210
CaSO i... C aC li... Ca(NO»)j... M g(H C O i)t... 20
MgSO<... 62
N aHCO a... N ajSO i... 80
N a C l... 10
N aN O a... 4
K C 1... 12
KNOa... S u m ... 429
Scale-forming con s titu e n ts ... 233
Foam ing constit- u e n ts ... 106 report iron as the 1
3 4 5 6 7
29 29 29 29 29
0 .7 0.7 0 .7
i .6 1 .6
36 8 126 130 210
147 147 68 68
19 4
96 96 96 96 24
60
94 128
83 83 83
io 10 20 20
4
12 Î 2
—LI - 1 1 - 1 1
430 428 430 427 427
255 257 236 235 236
80 82 105 103 103
and do not separate sodium one and potassium nitrate in the other. In C olu m n 3, however, calcium is combined first with sulfate instead of carbonate. In Co lu m n 4, calcium is c o m bined successively with sulfate, chlorine, and carbonate.
Columns 6 and 7 represent methods used b y certain boiler-water analysts, who ordinarily determine and
Ta b l e I I—Hy p o t h e t i c a l Co m b i n a t i o n s Re p r e s e n t i n g On e An a l y s i s
(S ee Ta b l e I)
1 2
29 i . 6 210
20 62 80 13 9 5 430 233 107
and potassium bu t com pute both together as sodium.
As these analysts would not determine nitrate in a water containing so little as t h a t under discussion absence of th a t radicle has necessarily been assumed.
Bicarbonates instead of carbonates also h ave been computed because analysis shows t h a t the carbonate radicle is absent; this slight deviation from the directed methods, however, makes no difference in the th eory and permits direct comparison with other schemes.
According to the scheme in C olu m n 5 calcium nitrate, instead of potassium or sodium nitrate, is co mputed.
According to th a t in Co lu m n 6 as much as possible of magnesium bicarbonate, is com puted first, while according to th a t in Co lu m n 7 as much as possible of calcium bicarbonate is com puted first.
T h e most obvious deduction from these figures is that it is impossible to compare the report of one an alyst with th a t of another w it h ou t recalculation. T h e next thou ght th at comes to most of us is t h a t the other man’s scheme is incorrect. Some would object to calculation of calcium nitrate at the expense of calcium carbonate and some to calculation of calcium chloride in the presence of sodium bicarbonate, while others would prefer to calculate magnesium sulfate instead of calcium sulfate. Aside from the theoretical merits of the methods, consideration of which would provok e endless discussion, there are these alarming facts:
(1) All are widely-used methods of reporting the analysis of one water.
(2) T h e results can not be directly com pared with one another.
(3) T h e results are used for estim ating the q uali ty of the water.
(4) T h e results are given to men who, not being chemists, are inco m pe tent properly to discount the statements bu t ta k e th e m at their face value.
One more digression m a y be permitted for the pur- pose of referring to the sums of the com puted co n
stituents. T h e sums in the last half of the table are a little lower than the others because nitrate and ferrous carbonate are disregarded. If these co n
stit uen ts h a d been c o m p ute d all the sums would ha ve been alike, the slight numerical differences am ong th em being due to casting off decimals. Reference is made to this ag ree m en t because some chemists, no dou bt thoughtle ssly , consider their metho ds of c o m bination correct because t h e y “ come ou t e v e n . ” One reports t h a t he n ever has a n y acid or base le ft over, or v e r y little, and another t h a t the sum of his calcu lated co nstituents agrees v e r y closely with to ta l solids b y evaporatio n. Th ese co m m en ts prove the excellent tec hn ique of analysis b u t not the chemical correctness of t h e co mbinations. Reference to the reac ting values in the first tab le m akes it obv ious th at, ex cep t b y error of analysis, there can be no surplus of base or acid and t h a t the sums m ust agree, no m att er how the radicles are co m bin ed or whether the combinations are logical.
T h e disagreement betw ee n C o lu m n i , in which so
dium nitrate is co m puted , and C olu m n 2, in which potassium nitrate is com puted, causes several e m barrassing numerical differences, and the l a y m a n under
sta nds t h a t one a n a l y s t found saltpeter where th e other did not. T h o u g h this difference m a y be pr ac ti ca ll y u nim p ortan t some similar ones m igh t lead to serious misunderstanding. W het her the belief is well fou nd ed t h a t li th ium is a v e r y va lu able ingredient of medicinal waters need not be discussed, b u t if it is desired to c o n v e y an id ea of the therapeutic effect of lithiu m the h y p o th e tic a l com bin ations are likel y to mislead those who are not aware of the lim itations of water analysis. If a water contains one part per million of lithiu m one can co m p ute 5.3 parts of lithiu m carbonate, 6.1 parts of lithiu m chloride, 7.9 parts of lithiu m sul
fate, or 9.7 parts of lithiu m bicarbonate. If the water had t h e p r o p e r ty of causing a n y physiologic reaction b y virtu e of its con tent of lithiu m it would exert th a t p ro p erty in proportion to its co nten t of the lithium radicle; y e t b y expressing t h a t conten t as lithiu m b i
carbonat e instead of the carbonate the conten t of lithiu m salts has ap p ar e n tly been nearly doubled and in t h e mind of the spring owner and his clientele, for w h om these com pounds are co m puted, the the rapeu tic value of t h e analysis, if not of the water, has been doubled.
I N T E R P R E T A T IO N O F R E S U L T S
In the co nventio nal metho ds of interpreting the various h y p o th e tic a l com binations there is general agree men t in some features and disagreement in others.
T a b l e I I shows the es tim ates of scale-forming and non- incrusting or fo am in g constituents t h a t the an alysts wo uld report agree fairly well with one another, the numerical differences bein g too small to cause essential difference in ju d g in g the value of the water. C o r responding es tim ates of the am ounts of soda ash and lime to soften the w at er would agree as closely as the sums of the constituents, because, alth ou gh each an alyst com p utes different constituents, he can not t h e r e b y chan ge t h e am ounts or relative proportions of the radicles with which the softening chemicals react.
In deciding whether the water would be corrosive there is greater div ersity of opinion. T h e analysts whose com bin ations are reported in Co lu m ns 3 and 6 appar en tly would sta te t h a t the water is non-corrosive.
7 1 2 T H E J O U R N A L O F I N D U S T R I A L
The man whose m ethod is shown in Column 5 would doubtless report the w at er to be slightly corrosive, as he com p utes calcium nitrate. T h e calcium chloride indicated in C o lu m n 4 could hardly be considered corrosive in presence of so m uch sodium bicarbonate.
In t h e other three sta te m e n ts magnesium sulfate but n o t calcium sulfate is reported, and there is in them no app arent reason for sta tin g whether the water is cor
rosive or non-corrosive.
C O M B IN A T IO N S U N N E C E S S A R Y
T h o u g h h y p o th e tic a l com bin ations are confusing and pu rely co nventio nal m a n y chemists assert that t h e y are necessary in ascertaining the value of a water and in c o n v e y i n g a proper kn owledge of the quality of th e water.
A s to the reported insistence b y the lay public so-called on h y p o th e tic a l com binations that can be understood it is pertin ent to inquire seriously how much an y series of ch cm ical figures means to the layman and whether it is not better to report the basic facts for the information of the expe rt a n d to ad d interpretations of the figures for the information of those who are unable to m a ke proper deductio ns for themselves.
R a t h e r in tim a te experience for several years with lay co m m en ts on w ater analyses has m a de me extremely skeptical as to h ow m uch of the truth hypothetical com bin ations c o n v e y to m a n y men who are supposed to m a ke pr ac tical use of the'results. W h a t the manu
facturer or engineer w an ts to kn o w is how a particular water will fit some use to which he wishes to put it.
Is it safe to drink? D oes it tas te bad? Will it stain clothes? H o w m uch scale will it form in boilers?
H o w can it be softened? A nswer ing these questions is th e fu nc tio n of an expert, who interprets the facts of analysis in th e ligh t of practical experience. It could be shown t h a t h y p o th e tic a l combinations are not necessary for answering these questions, though the discussion will be confined to in terpretation in reference to the rapeu tic va lu e and q u a lity for boiler use.
M IN E R A L W A T E R S
^ aters are an a lyzed more carefully and therefore more ex pensiv ely for ascertaining their therapeutic value th a n for a n y other purpose. Mineral salts that cause definite physiologic reactions when drunk cause the reactions in relation to the radicles t h a t are present.
A solution of m agn es ium sulfate, for example, can be so dilute t h a t it has no perceptible taste. A n equivalent concentration of sulfate in th e form of ferrous sulfate has a distin ct taste, and a solution of ferric chloride con taining in turn an equ iv a le n t concentration of iron has a similar taste, while again an equiva
lent concentration of chloride as sodium chloride has no perceptible taste. T h a t is, in the iron solu
tions we taste the iron and not the sulfate or the chloride, and in order to perceive the taste of the sulfate or the chloride radicle we must use a much stronger solution of a salt whose basic radicle is com
p a r a tiv e ly w eak in its effect on the organs of taste.
T w e n t y grams of magnesium sulfate has greater laxa
tiv e action th an 20 grams of sodium sulfate because the m agnes ium ion also induces l a x ativ e action whereas
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. 9
Sept., 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
7 1 3 the sodium ion does not, as can be shown b y an eq uiv
alent dose of sodium in the form of sodium chloride.
These rather crude illustrations serve to indicate that the physiologic action of a salt is caused b y one or more of the radicles co mposing the salt and is in pro
portion to their concentration. T h e probable cathartic effect of a sulfate water can therefore be measured b y its content of sulfate, co m p utatio n of the possible mathematical proportions of sodium, potassium, mag
nesium, and calcium sulfates being unnecessary.
The cathartic action of a water is increased b y its content of magnesium whether it m a y be possible to compute the magnesium as sulfate, chloride, or bi
carbonate. As for the minor constituents of mineral waters, lithium, bromide, iodide, manganese, strontium, and the like, it would not now be necessary to com bat so many fallacious ideas concerning their therapeutic value if serious consideration had heretofore been given to the concentration of these radicles instead of to the possible m a th em atic al com binations in which they might be reported.
B O IL E R W A T E R S
In a very condensed article, H. Stabler1 has shown how the scale-forming constituents, the foaming con
stituents, the te n d e n c y tow ard corrosion, and the quantities of softening reagents can be computed directly from the radicles w ith o u t recourse to h y p o thetical combinations. T h o u g h it has been objected that Stabler makes t h e same assumptions as are made in combining the radicles as salts this is true only in so far as his formulas are based on some of the currently accepted views of the reactions t h a t occur in boilers, concerning which much is y e t to be learned; and there remains the essential difference t h a t b y use of his formulas no theoretical salts, bu t the estimates that are helpful to the practical man, are obtained. C o m parison of the figures a t the ends of the preceding cables shows t h a t the es tim ate of scale directly from the radicles agrees closely with those based on com- mations. All unite in including silica, iron, and a uminum as the oxides; whether there is silicate in e scale, as some ha v e suggested, makes no arithmetical 1 erence in the to ta l. M a gn esiu m carbonate and magnesium sulfate are c o m m o nly included in total j>cale, though magnesium is prec ipitated mostly as the
•) rate under high-pressure conditions and the oxide etter represents w hat is found in the scale, as in stabler s formula. Some prefer to com pute the greatest Possible amount of calcium carbon ate and some the greatest possible a m o un t of calcium sulfate; calcium oubtless is precipitated in both forms and an average e ween them is struck in Sta ble r’s formula.
1 imilarly an aver ag e is struck am ong the three Possible sodium salts in co m p uting the foaming con- s-Kuents by m ultiplying sodium b y 2.7. Other con-
■ons besides the presence of a large amount of
■ >utn salts can cause foam ing, and some believe that sod^'11^ ^aS no N a t i o n to the concentration of the a° ,Un? salts- If, however, the interpreter of an a ysis believes t h a t th e sodium salts measure the h t t r En '. XeV!s‘ 60 (1908). 355; also U. S. Geol. Survey, W ater-Supply
» . J 7 1 (1910, 165.
foaming tenden cy he gets as good estimate of t h a t tenden cy b y multiplying sodium b y 2.7 as b y co m puting three different salts and ad ding the results together.
Corrosion is considered p artly a problem of reaction t h a t involves chiefly the setting free of acids b y pre
cipitation of magnesium as the hydrate. T h a t cor
rosion m a y be caused wholly or p artly b y other con
ditions need not concern us in discussing the practical interpretation of this theory. Stabler’s formulas pro
vide for the three possibilities. If there is not enough carbonate to combine with all the magnesium some sulfate or chloride would be set free and the water would be corrosive; under such condition those who compute hypothetical combinations report magnesium sulfate or magnesium chloride, the former of whiclT is classed as corrosive b y m a n y analysts and the latter universally as corrosive. If there is enough carbonate to satisfy or more th an satisfy both calcium and magnesium the water pr obably is non-corrosive;
under such condition it is cu stom ar y to com pute all the calcium and magnesium as carbonates, to giv e the excess to sodium, and to class the water as non-cor- rosive. Thus far boiler-water an alysts agree in so far as this theory of corrosion is accepted. If carbonate is sufficient to combine with calcium or magnesium alone but not with both, corrosion might or m ight not occur. T h e latter condition is th a t in the water under discussion, and the combinations in the second
I
.
table show th a t various analysts calculate diversely magnesium sulfate, calcium sulfate, and calcium n i
trate, and disagree as to whether corrosion would occur. T h e unce rta inty of the corrosive action is quickly revealed b y Stabler’s formulas without re
course to combinations. Corrosion occurs with waters t h a t would not be classed as corrosive b y a n y of these calculations, but t h a t is due to other conditions and its probability is revealed b y com putations of h y p o thetical combinations no more than b y consideration of the reaction of the radicles.
C O M B IN A T IO N S N O T E N D O R S E D
Evidence of desire on the part of chemists to break aw a y from conventional combinations of the co n
stituents found b y analysis is furnished b y the resolu
tions adopted b y various scientific organizations. A s early as 1886 a committee appointed b y the Ch em ical Society of Washington reco mm ended 1 th a t all analyses of water should be sta ted in terms of the radicles found, whether elementary or combined, meaning e v id e n tly expression of the im mediate results of the analysis;
though this committee recommended t h a t the co m bin a
tions deemed most probable b y the chemists m a king the analyses should also be reported it failed to recom
mend a manner of combination, and it is understood th a t the reason for lack of such recommendation is th a t the members of the co mmittee could not agree on one convention.
T h e report of this com m ittee was a d o p te d 2 b y Section C of the American Association for the A d vanc em en t of Science in 1887, and 2 years later a c o m mittee of the British Association for the A d v a n c e m e n t
* Bull. Chem. Soc. Washington, N o. 2 (1887), 35.
J Chem. News, 56 (1887), 113.
