uniform or new forms of shrinkage in the fabric d u r
ing the usual creping treatm ent in a ho t soap liquor is discussed and reference is made to large-scale experi
ments. “ Gaping ” (due to the presence of innum er
able small warp gaps resulting from irregular shrink
age) is avoided by entering the fabric into the soap liquor a t 90° instead of a t 100° as is usual.
A. J . H.
M e r c e ris a tio n of sta p le -fib re y a r n . W.
S ch ra m e k (Kunstseide u. Zellwolle, 1937, 19, 428—
432).—Max. swelling of natural cellulose occurs in 15—18% aq. NaOH, whereas this occurs in 10%
solution with regenerated fibres. The changes pro
duced by NaOH are best observed by X-rays. Two types of staple fibre are recognised : cuticle, i.e., fibres to which viscose and especially the stretched silks belong; and core, i.e., fibres comprising the Cu, acetate, and special types of viscose. Staple fibre should be mercerised only when unavoidable and the usual precautions for artificial silks should be taken.
Results are given of mercerising mixed yarns of cotton and staple fibre and of 50 repeated-washing tests of mercerised and unmercerised yarns and of the action of NaOH on single staple fibres. The usual techno
logical vals. are insufficient indication of the utility of a mixed yarn, and “ Dauerbiegfestigkeit ” (dura
tion of bending strength), which would include tensile strength, elongation, and elasticity, is proposed.
H . Wh. P re c a u tio n s n e c e s s a ry fo r p ro d u c in g g o o d w a te rp ro o fin g [of te x tile s ]. An o n. (Textilber., 1938, 19, 271).—I n waterproofing yarn or fabric by impregnating with 2-5—5-0% of R am asit K (I) it is recommended th a t the m aterial be free from alkali, acid, or wetting agents (e.g., sulphonated fa tty alcohols), and th a t th e subsequent drying be suffi
ciently slow for complete decomp. of ( I ) ; hard H ,0 should bo adjusted w ith AcOH. Drastic decatising of the waterproofed fabric m ay reduce its H aO-re- pellency. Increased H 20-repellency m ay be obtained by adding 1% of Al form ate or acetate (not sulphate) to the solution of (I) and by calendering the w ater
proofed fabric while it is slightly damp. A. J . H.
A p p lic a tio n of r u b b e r in th e te x tile in d u s try . P . B. G r i b n a u (Chem. Weekblad, 1938, 35, 218—
222).—A review. S. C.
D ifficu lties - i n th e c o m p le te im p re g n a tio n of te x tile s w ith [ru b b e r] la te x . J . C. Bo n g r a n d
(Gummi-Ztg., 1938, 52, 180—181).—The difficulties are enum erated and m ethods for obviating them, e.g., by using loosely twisted threads and dewaxed fibres, and ensuring a comparable p n in the textile m aterial and the latex (by increasing the p n of the former), are indicated. Im pregnation is additionally aided by removing the air from the textile m aterial by a vac,, increasing the time of contact w ith tho latex, prolonging the fluid condition of the latex on the threads by exposure to a moist ammoniacal atm ., and leading the thread through a coagulant bath when the latex in it has attained the state of a soft gel.
Applications are indicated for the treated m aterial obtained by the procedure described (which is, in p art, patented). Comment is made on the possibility of advantages to be derived from the use of
acid-stable Funtum ia latex for impregnation of textiles should this ever be commercially available.
D. F . T.
N ew s y s te m of o rg . s y n th e s is . R eco v e rin g d ir ty so lv e n ts e tc .—See I I I . S ilk fib ro in . R a y o n c re p e . B le a c h in g w o o d p u lp .—See V. A e ro p la n e fa b ric fin ish e s .—See X III.
Pa t e n t s.
P r e p a r a tio n of s u lp h o n ic a c id s a n d in so lu b le azo dy es [on th e fib re ] d e riv e d fro m th e s e a c id s . Soc. An o n, d e s Mat. Col. & Pr o d. Ch im. d e St. De n is, A . Wa iil, and M. Paillard (B .P . 479,708, 6.1.37. F r., 6.1.36).—Textiles composed either of vegetable or animal fibres are grounded with iV-sub- stituted derivatives of 2 : 1 -N H 2-Cj0H 6-S0.,H (I) and developed with diazo compounds derived from prim ary arylamines free from H 20-solubilising groups;
the S 0 3H is eliminated on coupling. Alternative modes of application a r e : (i) tho sulphonate and tho diazo compound in a form incapable of coupling, e.g., as a diazoimino-compound or an j'sodiazotate, are applied together and developed by a c id ; (ii) the sulphonate and arylamine are applied together and developed with H N 0 2; (iii) sulphonate, arylamine, and a nitrite are applied together and developed by acid. The sulphonic acid is m ade by interaction of (I), a sulphite, and a prim ary amine N H 2R, where R = a saturated aliphatic radical which m ay also contain a term inal amino- or acylamino-group.
Among examples there are described 2-methyl-, -n- bulyl-, and -i\-amyl-naphlhylamine-l-sulphonic acids and their N a salts and 'N-[i-a7ninoethyl-2-nuphthyl- amine-l-sulphonic acid [from (I) and (CH2-NH2)2], and its Ac, Bz, and n-CJI,M e-SO,y derivatives.
K . H. S.
C o lo ra tio n of te x tile a n d o th e r m a te r ia ls . H. Dr e y f u s and R. W . Mo ncrieff (B.P. 479,866, 13.8.36).—V at dyes dissolved in C5H 5N are reduced and the solution is diluted w ith petrol until the liquid contains 5—15% of org. base; tho solution is used to dye cellulose acetate fibres. K. H . S.
C o lo ra tio n of te x tile m a te r ia ls . H. Dr e y f u s
and R . W . Mo ncrieff (B.P. 479,867, 13.8.36).—
Textiles in package form, e.g., bobbins of cellulose acetate yarn, are dyed by circulation of a dye liquor containing a reduced v a t dye in aq. solution which contains about 10% of Pr^OH. Among examples, bobbins of cellulose acetate are dyed a t 50° for 2 hr.
with a v at made up of Ciba Blue 2B (10), NaOH (20), N a2S20 4 (40), H 20 (18,000), Pr^OH (2000 g.), Turkey- red oil (300), and aq. N H 3, d 0-880 (30 c.c.), and oxid
ised by circulation of a solution of alkaline H 20 at 60° for i hr. The dyeing is of very good uniformity.
K. H. S'.
P ro d u c tio n a n d d y ein g of m a te r ia ls fro m ce llu lo se e s te r s . L. S. E . El l is. From Soc.
Rh o diaceta (B.P. 480,297, 29.6.37).—Artificial resins obtained by polymerising N H 2-derivatives of CH2:CH-C02H or its a-substituted homologues are incorporated in cellulose esters and confer affinity for acid, direct, diazotisable, chrome, vat, and S dyes. I n examples, th e polymeride of CH2;CMe-C02C2Hj-NEt2 (I) (4) is dissolved with
Cl. VI.—B LEA C H IN G ; D Y EIN G ; P R IN T IN G ; FIN ISH IN G . 607 cellulose acetate (20) in COMe2 and affords threads
or films which are dyed w ith Diazol Pure Blue N FF.
A thread of similar properties is prepared by using the interpolymeride from the dicycZohexyl (65) and Me2 (35 pts.) analogues of (I). K . H . S.
D yeing w ith v a t d y es. J . G. Ke e n, Assr. to Na t. An i l i n e & Ch e m. Co., In c. (U.S.P. 2,067,927—9, 19.1.37. Appl., 8.4.35. Jap an , 3.9.34).—Improved results are obtained in both v a t dye pigm ent padding and printing processes by incorporating into the padding liquor or the printing paste sol. salts of-acid esters ( < C „ ) of polybasic inorg. acids (H2S 0 4, H 3P 0 4, H 3B 0 3, H 2S i0 4, boro-sulphuric and -phosphoric acids) from (a) aliphatic alcohols and (b) polyhydric alcohols.
The alkali salts are particularly effective, (o) covers the incorporation of the above compounds into v at dye baths used for straight dyeing. S. C.
P r in tin g of te x tile m a te r ia ls . E. I. D u Po n t d e Ne m o u r s & Co. (B .P . 479,847, 10.8.36. U.S., 10.8.35).—The H 20-sol. sulphate, or salt thereof, of an aliphatic prim ary or sec. alcohol of CG_,2, or a m ixture of such alcohols, containing branched chains (excluding chains first branched beyond C6 from the S 0 4H), is added to the printing paste for v a t dyes.
The alcohols are obtained as a fraction of b.p. 133—
260° in the fractionation of synthetic MeOH. The prints have improved levelness, penetration, strength,
and brilliancy. K . H. S.
P ro c e s s fo r re fin in g [w a te rp ro o fin g ] te x tile s . A. Ca r p m a e l. From I. G. Fa r b e n i n d. A.-G. (B.P.
479,753, 5.8.36 and 19.3.37).—Textiles are made H 20-repellent by esterification w ith anhydrides of dibasic carboxylic acids containing saturated or u n saturated open or cyclic chains of < C7, applied either as solution or emulsion, followed b y treatm ent with a base which still further reduces the capacity of the fibre to take up H 20 . Alternatively the esterified fibre is first treated with a base which forms a salt sensitive to H 20 and the latter converted by double decomp, into an insol. salt of Ca, Zn, or Al. Among examples, cotton fabric is treated for 15 min. a t 65°
with a 0-6% solution of isopentadecenylsuccinic anhydride in CC14 and when dry rinsed in hard H 20 for 5 min. a t 80°, dried, and again rinsed, whereby Ca salts are formed which render the fabric waterproof.
Similarly artificial silk is im pregnated w ith n-octa- decenylsuccinic anhydride, treated with dil. aq.
N a9C 0,, and th en treated with dil. aq. ZnCL.
K H . S . T r e a tm e n t of ce llu lo se e s te r s a n d m a te r ia ls c o m p ris in g th e s a m e . Br i t. Ce l a n e s e, Lt d. (B.P. 473,004, 3.4.36. U.S., 3.4.35).—Filaments, yarns, and fabrics of cellulose esters (especially cellu
lose acetate) are subjected to a dam p atm . and saponi
fied while still possessing a high moisture content.
Saponification can also be carried out by subjecting the m aterials (which m ay have been conditioned in a m oist atm .) to a prelim inary saponification sufficient to produce only a small loss in wt. (2—7%) and completing th e saponification, w ithout removing the reaction products, w ith a substance less alkaline (Ph 8—11) th an th a t used initially (e.g., w ith soap, NaOAc, etc.). E.g., acetate y a m (COMe2-sol.) is ex
posed a t R .H . > 6 5 % until the moisture content is
n n (b.)
4% , and saponified with 20% aq. NaOH to give a 5%
loss in wt. Saponification is completed by treating the unwashed yarn with a 10% aq. soap solution a t 90° for I hr. The final loss in wt. is 10% and the product has affinity for cotton dyes. Local saponi
fication m ay also bo carried out by this process.
R. J . W. R.
T r e a tm e n t of y a r n s , fila m e n ts , fa b ric s , a n d lik e m a te r ia ls . Br it. Ce l a n e s e, Lt d. (B.P.
473,005, 3.4.36. U.S., 3.4.35).—Indicators which have no affinity for and can easily be removed from the m aterials are applied to m aterials of regenerated cellulose or cellulose derivatives to indicate changes in p a which occur during treatm ent with acids or alkalis, e.g., in saponification, creping, etc. They are conveniently applied as a solution or dispersion in a lubricant. In an example, Violet 5BK (4) is dis
solved in sulphonated naphthene (20) and the solution dispersed in light mineral oil (75 pts.) to give a com
position useful as the indicator in the local saponi
fication of cellulose acetate yarn. R . J . W. R.
M a n u fa c tu re a n d t r e a tm e n t of te x tile m a te r ia ls [w e ig h tin g , d e lu s trin g , e tc .]. Br it. Ce l a n e s e, Lt d., G. H. El l is, and A. J . We s s o n
(B.P. 472,905, 1.4.36).—H 20-insol. m etal compounds are incorporated in textile m aterials (especially those composed of cellulose esters or ethers) by treatm ent with two m etal salts which interact to give insol.
derivatives. The m aterial can be treated with a third reagent (after application of one or both salts) which will convert suitable salts into compounds capable of interacting with each other. E.g., material is treated with aq. Ba(CNS)2, then with aq. Na2C03, and finally with aq. A l^ S O ^ . Softening agents, e.g., glycerol, m ay also be present. R. J . W . R.
T r e a tm e n t of c o tto n fa b ric . C. B . Wh i t e, Assr.
to W . E . Ho o p e r & So n s Co. (U.S.P. 2,061,686, 24.11.36. Appl., 14.9.33).—A film of cellulose is formed on the m aterials by superficial treatm ent with cuprammonium solution to dissolve a portion of the fibre, and the Cu salts are then removed by applic
ation of N a2S20 3 solution. The treated m aterials resemble linen and are o f good colour.
R. J . W. R.
P o ro u s ad h e siv e fa b ric s . D. Sa r a s o n (B.P.
479,795, 28.1.37. Ger., 29.1.36).— Open-mesh fabric for bandages or the like is treated with non-viscous (3—6%) solution of rubber, in such q uantity th a t the mesh remains open, and is dried by hot air, with slight vulcanisation if desired. B. M. V.
I m p re g n a tio n [of p ile fa b ric s ]. G. S. Hi e r s, A ssr. to Co l l in s & Aik m a n Co r p. (U.S.P. 2,062,178, 24.11.36. Appl., 31.7.34).—The fibres in a loosely-woven pile fabric in which the tu fts form bights on the back are rendered secure by treating the m aterial with a non-vulcanisable, aq. dispersion containing rubber, a non-tacky wax, and, if desired, antioxidants.
The fabric is then heated to coagulate the rubber and melt the wax so th a t the latter forms a “ bloom ” on the surface of the coating and prevents tackiness.
Scouring, dyeing, etc. m ay th en be carried out. The presence of the pile bights prevents the form ation of a continuous backing coating. R. J . W. R.
508 B R IT IS H CHEMICAL A M ) PHYSIOLOGICAL ABSTRACTS.—B.
[P o ly iso b u ty len e ] im p r e g n a te d fib ro u s m a te r i a l. P . K. Fr o l ic h and P . J . Wie z e v ic h, Assrs.
to St a n d a r d Oil De v e l o p m e n tCo. (U .S .P . 2,061,570, 24.11.36. Appl., 19.7.33).—Fabrics, paper, leather, wood, etc. are coated or im pregnated w ith a poly
meride (I) of j'sobutylene (obtained, e.g., by treatm ent with an inorg. halide a t < —10°) to give products which are w aterproof and resistant to oxidation, rotting, and corrosion. (I) is preferably used in org.
solution, e.g., in CC14 or naphtha, to which fungicides etc. m ay be added, and the solvent evaporated from the im pregnated material. Tacky finishes are ob
tained by the use of a solution (< 2 0 % ) of (I) of mol.
wt. 1000—5000, whilst the use of a solution (< 2 0 %) of (I) of mol. wt. 5000—10,000 gives a w aterproof finish. (I) m ay be added to dry-cleaning solvents to render the shape of cleaned garments more durable, and also used for carpet backing and as an interlayer
in two-ply fabrics. R. J . W. R.
D ire c t cold p e r m a n e n t w a v in g [of h a ir ] . J . Y. Ma l o n e, J . H. Ca r r o l l, and C. R . McKe e, Assrs. to Pe r w a y Co. (U.S.P. 2,061,709, 24.11.36.
Appl., 24.7.33).—H air is treated a t about room temp, with a softening composition (I) (pa 9—14) contain
ing a basic compound (preferably of a reducing nature) of an am photeric metal, and then waved, after which is applied an acidic fixing m aterial (II) (e.g., an acid salt or org. acid) which destroys the action of (I).
A conc. solution (I II) of a neutral salt m ay finally be used to remove excess of (I) and (II). Reducing agents, e.g., alkali sulphides, to prevent atm . oxid
ation, and enzymes m ay be added to (I). (II) and (III) m ay contain reagents to interact with any S compounds formed during treatm ent. E.g., (I) is an aq. solution of N a2SnO„ (0-01—4%), N a2S20 4 (0-5—
2%), Na2S„ (< 2 % ), and. trypsin (0-001— 10%); (II) an aq. solution of A12(S04)3 (10—50%) and ZnS04 (5—15% ); and (III) an aq. solution of NaCl (10—
30%). R. J . W. R.
[M ech an ically ] fo r m in g d e s ig n s on fa b ric s . L. and J . Re y o h l e r (B.P. 481,284, 5.8.36. Belg., 7.
and 9.8.35).
T e x tile a s s is ta n ts . W e ttin g etc. a g e n ts .—See II I. A zo d y e s.—See IV. R u b b e r y a r n s etc.—
See XIV.
VII.—A C ID S ; A L K A L I S ; S A L T S ; NO N -M ETA LLIC ELEMENTS.
P ro d u c tio n of s u lp h u ric a c id fr o m m o is t g a s b y tb e c o n ta c t p ro c e s s . I. E. Ad a d u r o v, O. N.
Tz e it l in, and T . L. Fo m it sc h e v a (Ukrain. Chem. J., 1 9 3 8 ,1 3 ,1 —5).—Optim um conditions for production of H 2S 0 4 from dam p S 0 2 are : Ph.o/Pso, = 18—19 (where P H,0 and P SOl are the partial pressures of H 20 and S 0 2), [S 02] 4—6% , contact tem p. 480°, temp, gradient of the condensation zone 380—200°, and condensation tim e 10—11 sec. 80—99% H 2S 0 4 is thus obtained in theoretical yield. R. T .
[M a n u fa c tu re of] s u lp h u ric a c id b y tb e le a d c h a m b e r p ro c e s s . L a b o r a to ry e x p e rim e n t.
H. A. Sm it h (J. Chem. Educ., 1937,14, 479).
L. S. T.
C o lo rim e tric d e te r m in a tio n of n itr ic a c id in s p e n t s u lp h u ric a c id . Pe k k e r (Zavod. Lab., 1937, 6, 1280).—0-5 ml. of acid is added to 8-5 ml. of conc.
H 2S 0 4 and 1-5 ml. of 4—5% F eS 0 4, and the red coloration developing is compared with th a t given by a series of standard solutions containing 0-01:—1% of
H N 0 3. R .T .
P a c k in g m a te r ia ls fo r s u lp h u ric a c id to w e rs . II . G. Os a m e (J. Soc. Chem. Ind. Japan, 1937, 40, 434— 435b; cf. B., 1937, 1333).—W hen streams of H ,0 and H 2S 0 4 (d 1-52 and 1-70) flow a t equal rates down vertical surfaces the widths of the streams are approx. eq u a l; . roughness has no appreciable effect.
Only small quantities of H 20 were required to remove dye from square packing, Raschig rings packed regularly, or from 2-holed bricks packed flat, bu t random-packed Raschig rings and spiral rings were not completely washed out even with larger quantities of H 20 . W ith square packing the am ount of H 20 which flows inside or out is oc the area, b u t with Raschig rings piled tetrahedrafiy much more H 20 per un it area flows outside th an inside. I. C. R.
D e te rm in a tio n of s u lp h u ric in c o n c e n tra te d n itr ic a c id . Ko t e l n ik o v (Zavod. Lab., 1937, 6, 1280—1281).—20 ml. of formalin and 10 ml. of H 20 are added to 10 g. of H N 0 3, and the m ixture is evaporated to small vol., 2—3 drops of formalin are added to the residue, and, should fu rther NO n o t be evolved, H 2S 04 in the solution is titra te d with standard
alkali. R . T.
E ffects of a d d itio n of c o m m o n s a lt d u r in g c a lc in a tio n of lim e s to n e . V II. M ic ro sc o p ic a l o b s e rv a tio n of q u ic k lim e . T. No d a (J. Soc.
Chem. In d. Jap an , 1937, 40, 417—418b; cf. B., 1937, 1042).—Photom icrographs show th a t CaO prepared by calcining CaC03 a t 1000° is a loose aggregate of m inute globular crystals (1 (x.); calcination a t 1300°
yields 3 jx. crystals, and a t 1670° a hard mass of rounded 20—60 (j.. crystals. I n presence of NaCl the CaO is a loose porous aggregate of globular polyhedra of uniform size, 4 (j.. a t 1400° and 11 u. a t 1300°. A t 1300°, when some NaCl has condensed on th e crystals, 15 (x. cubes are formed. I. C. R.
A m m o n ia -s y n th e s is c o lu m n fo r te s tin g of c a ta ly s ts . V. M. Gr i n e v it s c h (Zavod. Lab., 1937, 6, 1493—1494).—A pparatus is described. R. T.
P r o d u c tio n of s o d iu m s u lp h id e in r o ta tin g ovens. N. F. Li a m i n (J. Appl. Chem. Russ., 1937, 10, 2001—2007).—NajSO,! is mixed intim ately with powdered coke (gram diam eter 2—5 mm.), and air a t 1100° is passed through the m ixture in a rotating o v e n ; the product contains 75—80% of NagS. The dura
tion of the process depends on the size of the oven and the m agnitude of the charge. R. T.
R a p id d e te r m in a tio n of m a g n e s iu m i n m a g n e s ite s a n d d o lo m ite s . S . I. Sc h o d t z e v and V. I.
Bl a g o v e s c h t s c h e n s k a j a (Zavod. Lab., 1937, 6, 1484— 1485).—The sample is dissolved in HCl, and a vol. of solution corresponding w ith 0-1 g. of the sample is m ade exactly neutral (neutral-red) w ith N-NaOH and 0-lN-Ba(OH)2, 100 ml. excess of which is added, followed by H 20 to 250 ml. The solution is filtered and an aliquot p a rt of the filtrate is titra te d
(neutral-C l. V II.—ACIDS; ALKA LIS; SALTS; NON-METALLIC ELEM ENTS. 509 red) w ith 0-05n-HC1; the Mg content is calc, there
from. R. T.
D e te rm in a tio n of c a lc iu m n itr id e in c a lc iu m c y a n a m id e . A. A. Ko r i n f s k i (Zavod. Lab., 1937, 6, 1440—1442).—25 ml. of 3% H 2S 0 4 are added gradually to 1—1-5 g. of CaCN2, a stream of air being aspirated through the flask and then through 25 ml.
of 3% H 2S 0 4. The two solutions are then mixed, 10 ml. of 10% Pb(OAe)2 aro added, and the solution is filtered. 10 ml. of 5% citric acid solution are added to the filtrate + washings, and the solution is made neutral to phenolphthalein with O-Sx-NaOH, 10 ml. of neutral 40% aq. C ll20 are added, and the solution is titrated with O-lN-NaOH. Ca3N2 % = 0-740852®/w, where w is the wt. of the sample and a the no. of
ml. of O-lN-NaOH used. R. T.
O re -d re s s in g p ra c tic e w ith F lo r id a p eb b le p h o s p h a te s , S o u th e rn P h o s p h a te C o rp o ra tio n . J . W. Pa m p l in(Min. Tech., 1938, 2, Tech. Publ. 881, 19 pp.).—P lan t handling approx. long tons of phosphate pebbles (6G—80% of Ca,P20 8) in 4000 gals, of H 20 per min. is described. The process consists in ridding the phosphate pebble of all clay and then separating fine phosphate pebble from quartz of the
same sizes. A. K. G. T.
R e a c tio n of p h o s p h a te s w ith s u lp h u r m o n o c h lo rid e . S y s te m s c a lc iu m o rth o p h o s p h a te -, K u rs k p h o s p h o rite -, a r tific ia l a p a tite - , a n d C h ib in a p a tite - s u lp h u r m o n o c h lo rid e . A. P.
Pa l k in and L. F . De n is o v a (J. Appl. Chem. Russ., 1937, 10, 1993—2000).—Phosphates react with S2C12 a t room tem p, as follows : 2Ca3(P 0 4), -f- 6S2C12 = 6CaCl2 + 2P20 5 + 3S 02 + 9 S ; 2P20^ + 6S2C12 = 4P0C13 + 3S02 + 9 S ; P0C13 + 3H20 = H 3PO.; + 3HC1. The process is complete in 24 hr. R . T.
E x a m in a tio n of c o m m e rc ia l c a lc iu m a r s e n a te s . O. A. Ne l s o n and C. C. Ca s s il (J. Econ. Entom ., 1937, 30, 474— 478).—Analytical d ata are recorded.
The commercial product contains 40—47% of As2Os and 30—40% of combined CaO, together with free Ca(OH)2, CaC03, and minor impurities. N o relation is apparent between the proportion of free Ca(OH)2 and the % of H 20-sol. As. Individual brands of Ca arsenate vary considerably in CaO/As2Os ra tio ; wider differences occur between different brands [free Ca(OH)2 and CaC03 being excluded]. H 20-sol. As tends to diminish with increase in % of fine particles and w ith increase in the CaO/As2Os ratio. Commer
cial samples probably contain CaHAs04,H20 and a basic solid solution of tri- and tetra-calcium arsenates.
A. G. P.
P a rtic le size of c o m m e rc ia l c a lc iu m a r s e n a te s b y s e d im e n ta tio n a n a ly s is . L. D. Go o d h u e (J.
Econ. Entom ., 1937, 30, 466—474).—Size distribution of particles is determined by sedimentation in E tO H - H 20 (1 : 1). The loose bulking val. is an unreliable measure of particle size. A relation between particle size and d is indicated. A. G. P .
M a n u fa c tu re of zin c o xide. A. G. El l io t t (Oil and Col. Tr. J ., 1938, 93, 674—679).—A review.
The development of different methods for the m anu
facture of ZnO is traced historically, and modern methods, including the production of acicular and
small particle-size ZnO (for rubber compounding), are described. The properties and uses of the different products and the causes of discoloration are discussed.
D. R, D.
W e t-c h lo rin a tio n p ro c e s s fo r p r e p a r a tio n of zinc c h lo rid e . V. Pr is t o u p il (Chem. Obzor, 1937, 12, 217—221).—The usual wet process using Cl2 gas is simplified for flotation blende by om itting the FeCl3 catalyst, which has otherwise to be removed from the product. The products are ZnCl2 solution of arbitrary concn. and elem entary S. The process, which re
quires I— J of the to tal Zn to be added as roasted blende, is regarded as solved technically, bu t as pre
senting no economic advantage over present practice.
F. R.
P r e p a r a tio n of p u r e a lu m in a fro m M a n c h u r ia n a lu m in o u s s h a le . I I . T r e a tm e n t of F u k u s h u s h a le w ith a m ix tu r e of s u lp h u ric ac id a n d a m m o n iu m s u lp h a te u n d e r p r e s s u r e . T.
P r e p a r a tio n of p u r e a lu m in a fro m M a n c h u r ia n a lu m in o u s s h a le . I I . T r e a tm e n t of F u k u s h u s h a le w ith a m ix tu r e of s u lp h u ric ac id a n d a m m o n iu m s u lp h a te u n d e r p r e s s u r e . T.