—LEATHER; GLUE

A ir-perm eability of leather. R. S. Edw a rd s

(J. Soc. Leather Trades’ Chem., 1930, 14, 392—409).—

The air-permeability of different leathers was measured in two ways (methods A and B). In A the specimen was clamped to the end of a glass tube placed in series with a capillary tube of known dimensions and air drawn through them successively by means of a suction pump. The pressure a t each end of the capillary was measured by means of tubes connected to vertical tubes dipping into a mercury trough. The volume of gas permeating the leather was calculated from Meyer’s

formula for the flow of gas through the capillary tube and the permeability was calculated therefrom. In method B a convenient volume of gas was evacuated from an enclosure which was connected to a mercury column and also to a tube fitted with a tap, and a t its end an ordinary rubber plunger. The latter was placed on the sample of leather, the tap opened, and the time noted for the pressure in the enclosure to increase to a certain value. Determinations by method A showed th a t patent leather was non-porous. The order of increasing permeability of other leathers was ; stuffed vegetable-tanned upper leather, French sole leather, waterproofed English sole leather, heavy chrome-tanned upper leather, English sole leather, glacé kid, gorse calf, willow calf, box calf, vegetable- tanned calf (Russia). The permeability in the direc­

tion flesh to grain was about 2% greater than in the opposite direction. Comparison of the permeabilities of different parts of a chrome-tanned calfskin by method B gave widely varying results (20—110).

D. WOODROFI-E.

See also A., Sept., 1118, S w ellin g of gelatin in acid and sa lt solution s (von Moraczew ski and Grzycki).

1223, Kola tannins (Ca s p a r is and Re b e r).

Pa t e n t s.

L eather-dressing p rocess. O. L. St e v e n (U.S.P.

1,750,732, 18.3.30. Appl., 30.6.28. Ger., 22.7.27).—

Synthetic tanning agents or ligninsulphonic acids are fixed in leather by soaking the leather in a solution of a salt of aniline, benzidine, or naphthylamine prior to

finishing. C. Ho l l in s.

Production of artificial m a sses from casein.

O. Sch m idt, K. Se y d e l, and E. Me y e r, Assrs. to I. G.

Fa r b e n in d. A.-Ô. (U.S.P. 1,775,175, 9.9.30. Appl., 12.9.27. Ger., 27.8.26).—See B.P. 297,483 ; B., 1928, 869.

Manufacture [com pacting and finishing] of [vegetable-tanned sole] leather. C. G. Sh a w (B .P . 333,871, 19.2.29).

A rtificial leather (B.P. 317,824).—See V. P re­

paration of leather cloth (B.P. 332,602).—See VI.

X V I.— AGRICULTURE.

Soil acidity. W. U. Beh r e n s (Z. Pflanz. Diing., 1930, 18A, 5—44).—Existing methods for determining the degree of saturation of soils with bases are largely conventional, since the total adsorptive capacity of soils varies greatly with the concentration of the neutral salt solution with which it is treated. The value (T — (S') is preferably determined by treating soil with O-OLV-sodium borate, the unadsorbed alkali being subsequently determined by titration. Although by this process the soil suspension is m aintained a t 8-0—10-0, the adsorptive capacity of the soil is increased by about 3%. Relations between the p R values of soil suspensions in water and in potassium chloride solution, the degree of salination, and exchange acidity are examined. W ith V = 0-5, p n (water) = 5-5, p u (KCl) = 4-6, and exchange acidity = 0 - 2 c.c. of 2\7-acid per 100 g. of soil. Treatm ent of neutral soils with potassium chloride solution causes an exchange of

B r itis h C h e m ic a l A b s tr a c ts^— B .

1000 C l. X V I.^{— A}g r i c u l t u r e.

potassium for aluminium, thereby producing a type of exchange acidity characterised by a decreased p a and an increased titratable acidity in the solid phase.

Hydrolytic acidity is determined from the amount of potassium hydroxide necessary to produce the same p n in the soil suspension as is obtained by shaking soil with acetate solution, and values are compared with the amount of acetic acid liberated in this manner.

In mineral soils the acid produced approaches the equivalent of the direct potash consumption, but in organic soils there is a deficit ascribed to the adsorption of acetic acid by the humus. Humus soils when shaken with neutral salt solutions liberate their maximum titratable acid very rapidly, and it is suggested th a t organic acids and aluminium salts exist normally in such soils in an adsorbed condition. Curves expressing relationships between the pn and the buffer capacity of soils ( As/A^h, where As — quantity of acid pro­

ducing a change of A pu in a soil) show minima between p n 5 and 6-5. In the acid area two components of the curve are differentiated, viz., buffering due to the libera­

tion of “ perm utit acids ” and th a t resulting from the dissolution of alumina from the silicate complex. Soils and added acid do not attain complete equilibrium within 3 days. A. 6 . Po lla r d.

C olorim etric determ ination of p H values in alkaline s o ils. P. Kam er4ia x (J. S. Air. Chem. Inst., 1930, 13, 59—63).—Colorimetric methods for deter­

minating values gave unsatisfactory results. Dis­

crepancies are probably due to hydrolytic effects brought about by the increased w a te r: soil ratio necessitated by th e preparation of a filtered soil extract.

A. G. Po l l a r d. Rapid colorim etric determ ination of citric- solub le phosphoric acid in soils? A. Nemec, J.

La n ik, and A. Koppova (Compt. rend., 1930, 191, 69—71).—The soil (10 g.) is stirred with 100 c.c. of a 1% solution of citric acid, and 5 c.c. of the solution, after filtering and centrifuging, aTe acidified and titrated with potassium permanganate solution at the b.p.

Dilute hydrogen peroxide solution is added to destroy the excess of permanganate, and the solution is neutral­

ised with ammonia, using dinitrophenol as indicator.

Then 2 c.c. of ammonium molybdate solution and 0-3 c.c. of stannous chloride solution per mg. of P 20 5 present are added, and the blue colour of the solution after dilution to 100 c.c. is compared with th a t given by a known am ount of citric acid.

H. F. Gil l b e. D eterm ination of the adsorption capacity [of so ils]. S. N. Al e sc h in (Z. Pflanz. Dung., 1930, 18A, 44—48).—Modifications of the Bobko-Askinasi method are described. The soil is saturated with barium by shaking with barium chloride solution and then trans­

ferring to a filter and washing with more barium chloride solution until all calcium is removed. The soil is further washed with water until free from chloride. Adsorbed barium is determined by shaking the washed soil with excess of 0-05Ar-sulphuric acid (500 c.c. per 10 g. of soil used) and, after filtration, titrating the residual- acid with soda. To ensure the soil being treated with exactly the same concentration of acid, the washed sample may be dried in an oven before treatm ent, or,

if used wet, the moisture m ust be allowed for. The washing out of the excess of barium chloride in the initial process may be replaced by precipitation with sulphuric acid. A. G. Po lla rd.

D eterm ination of total carbonates in so ils.

A. N. Pu r i (Bull. Imp. Inst. Agric. Res., P u sa , 1930, No. 206, 7 pp.).—Ten g. of soil are stirred with 100 c.c.

of water and excess (0-2—0-5 g.) of calcium sulphate is added. The mixture is heated to boiling, 10 c.c.- of 0-1 /Y-aluniinium chloride are added, and the mixture is shaken. About 10 drops of a 1% alcoholic solution of bromothymol-blue are added and, after vigorous shaking, the suspension is allowed to settle. A yellow colour in the supernatant liquid indicates < 1% of carbonates in the so il; a green to blue colour, above 1% of carbonates. The colour is again noted after the further addition of 10 drops of 1% alcoholic solution of bromocresol-green. When no carbonate is present the colour is golden-yellow; with < 1%, green; and with ^ > 1 % , deep blue-green. The suspension is again heated to boiling and titrated with 0 • SiY-sulplmric acid, boiling being continued for 2 min. after each addition of acid. Complete decomposition of carbonates is indicated by a golden-yellow colour which persists after boiling and allowing the suspension to settle.

A. G. Po l l a r d. S ilage investigation s at Bangalore. T. S. ^{BLr i s h-}

n a n (Mem. Dept. Agric. India, 1930, 10 , 237—259).—

Chemical changes occurring during the ensilage of Sorghum vulgare are examined. Protein changes resemble those occurring under European conditions. A high ratio of volatile base : amino-acid is possible without deterioration of the silage. Butyric acid was absent from all samples examined. During ensilage there is a considerable loss of phosphate and of some calcium in the drainage, together with smaller amounts of chloride, alkalis, and magnesium. The sulphate content of the silage increased, presumably as a result of the oxidation of protein-sulphur. A. G. Po l l a r d.

C hem ical m ethod for determ ining fertiliser requirem ents [of so ils] and the action of phosphatic fertilisers. A. Nem e c (Z. Pflanz. Diing., 1930, 18A, 48—56).—Lack of agreement between field trials and laboratory tests of the phosphate requirement of soils is attributed to interaction between soil and fertiliser in the field, which is not adequately represented in laboratory tests. The efficiency of phosphate fertilisers is affected by the nature and proportions of soluble cations in th e soil. In soils containing more than 50 mg. of citric-soluble iron per 100 g. of soil, phosphate fertilisers may not exert their full effect on crop yields.

This effect is most marked in soils originally poor in phosphate. The author’s method for determining phosphate requirements (B.; 1929, 420, 938) is supple­

mented by a determination of iron soluble in 1% citric

acid. A. G. Po l l a r d.

T he m ixed fertiliser “ N itrophoska. ’ ’ W . We r n e r

(Z. Pflanz. Diing., 1930, 9B , 339—360).—P ot cultures with a number of crops show th a t in sandy soils of small adsorptive power, “ Nitrophoska,” used in conjunction with lime, may cause plant injury by the liberation of free ammonia, and actual losses of nitrogen may occur

B r itis h C h e m ic a l A b s tr a c ta —B . i p o u n í

cł. x v i l-- S t j q a r s ; S t a r c h e s ; G u m s . C^l. X V III.— F e r m e n t a t i o n I n d u s t r i e s . - , / V 1001

•where heavy dressings of lime are applied. In weakly acid sandy soils the water-soluble phosphate in Nitro- phoska is transformed into a relatively unassimilable form (probably iron or aluminium phosphate). In such soils superphosphate was much the more efficient, but on very acid soils the superiority of superphosphate was not observed. On loams Nitrophoslca gave better crop yields than superphosphate and, in general, may be recommended for use on weakly acid to neutral

soils. A. G. Po l la r d.

Field m anurial trials w ith N itrophoska. F.

Honcamp and H . WffiSSMANN (Z. Pflanz. Diing., 1930, 9B , 361—363).—In field trials with potatoes and roots Nitrophoska proved as efficient as did corresponding mixtures of the simple fertilisers. A. G. Po lla rd.

“ H u m in it.” K. Eckl (Z. Pflanz. Diing., 1930, 9B , 378—382).—In fertiliser trials the addition of

“ H um init (cf. Densch., B., 1929, 532) to farmyard manure did not increase its crop-producing power.

A . G. Po lla r d. M odern pasture m anagem ent and nitrogen m anuring. Moller (Z. Pflanz. Diing., 1930, 9B, 363—377).—Results of meat and milk trials on the intensive grazing system are recorded. The efficiency of nitrogenous fertilisers in this practice is largely dependent on weather conditions. Tables of costs and returns are given for a number of fertilisers.

A. G. Po lla r d. Effect of rye and vetch green m anures on the m icroflora, nitrates, and hydrogen-ion concen­

tration of two acid and neutralised so ils. N. R.

Sm ith and H . Hu.m feld (J. Agric. Res., 1930, 4 1 , 97— 123).—On both acid and neutral soils green manuring increased the number of micro-organisms developing on soil extract-agar plates. Maximum numbers were reached in 4—5 days and subsequently decreased rapidly as the leafy portions of the manure disappeared. On soils neutralised with chalk, but not on acid soils, a later increase in bacterial numbers occurred, this phenomena being characteristic of the first application of green manure only. The number of fungi appearing in acid and neutral soils was not affected by green manuring.

N itrate accumulation was increased by manuring. A slightly increased acidity coincided with nitrate produc­

tion in unlimed soils, the effect being more marked in sandy than in clay soils. A. G. Po lla rd.

Control of the stalk borer in m aize. L. B. Rip l e y

and G. A . He p b u r n (Farming in S. Africa, 1929, 4, 353—354).—Cryolite (1 in 600, suspension) is an effective stomach poison; sodium chromium fluoride is less poisonous. Ch em ical Ab s t r a c t s.

U se of sod iu m chlorate in the control of Johnson g ra ss. H . J. Ha r p e r (J. Amer. Soc. Agron., 1930, 22, 417—422).—Sulphuric acid is not so effective as sodium chlorate. Soils treated with sodium chlorate have a lower nitrifying power than untreated soils.

Chem ical Abstra cts. D eterm ination of the quantity of oil retained by citrus foliage after sp raying. L. L. En g l ish (J.

Agric. Res., 1930, 41, 131—133).—As soon as the oil spray on foliage has dried, 50 sample leaves are collected from various parts of the tree and a disc 10 cm.2 in area is punched from each leaf. The discs are shaken with

50 c.c. of ether for 1 min. and the extract is filtered.

A second extract is made and the combined solutions are evaporated to 20—25 c.c. and placed in a Babcock skim-milk bottle with 5 c.c. of approx. 0-5Ar-sulphuric acid. Residual ether is removed by heating to 50°, the tem perature slowly raised to 80°, and sufficient hot acid added to bring the oil into the capillary. The bottle is centrifuged in a heated centrifuge and the oil volume measured. Repeated heating and centrifuging may be necessary to produce complete separation of the

oil. _ A. G. Po l l a r d.

P etroleu m oil for sp raying. De On g.—See II.

See also A., Sept., 1109, Calcium hydroxide ab sorp ­ tion b y hydrated silica (Sha w and Ma cIn t y r e).

Pa t e n t s.

Production of m ateria ls containing phosphorus and nitrogen suitable for use as fertilisers. Hydro

Nitro Soc. An o n. (B.P. 333,477, 19.11.29. Switz., 1.12.28).—Phosphorus pentoxide is heated under pres­

sure in an autoclave with ammonium carbam ate or with ammonia and carbonic acid, yielding a mixture of urea and ammonium phosphates. L. A. Co l e s.

D erivatives of arom atic diazo com pound (B.P.

309,610).—See IV. Calcium cyanam ide (B.P. 333,353).

—See VII.

XVII.— SUGARS ; STARCHES; GUMS.

Colloids [cane w ax] in granulated su gar. C. F.

Bar do rf (Ind. Eng. Chem., 1930, 22, 907).—The claim th a t certain granulated sugars contained colloids (highly dispersed cane wax) capable of coagulating the flavouring extract used in the preparation of beverages was exam­

ined. Macroscopical inspection of the sugar crystals, observation of a thick layer of a 50% solution, and a percolation test were made and the results compared with those given by a flocculation test. No conclusions could be drawn as the sugars of best quality from the refiner’s point of view were often the most unsatisfactory as regards the coagulation. I t is considered significant th a t the most severe flocculation was in all cases produced by sugars refined from N atal raws.

H . J. Do w d e n. Effect of h eat on acacia. Ga b e l.—See XX.

See also A., Sept., 1151, M easurem ent of turbidity (Ing er so ll). 1167, C olorim etric determ ination of starch (Paloheimo). Separation of com ponents of potato starch (Ba l d w in).

X V ffl.— FERMENTATION INDUSTRIES.

D eterm ination of [ethyl] alcohol [by chrom ic oxidation]. L. Semichonand M. Fla nzy (Ann. Falsif., 1930, 23, 347—349 ; cf. B., 1929, 449).—The authors acknowledge the priority of Martin, b u t m aintain th a t they have introduced im portant refinements, viz., separate oxidation and distillation operations, different concentration for the oxidising agent, and oxidation in the cold. H . J. Do w d e n.

C hem ico-brom otological stu d ies on vin egars. U.

Pratolongo [with, in part, M. P . Al l a n] (Giorn. Cliim.

Ind. Appl., 1930, 12, 335—340).—Italian legis’ation of October, 1925, forbids the use as food products of

B r itis h C h em ica l A b s tr a c ts^— B .

1002 Cl. X IX .—Fo o d s.

synthetic or distilled vinegar, and the coloration of alcohol vinegar or of wine vinegar, even with colouring m atters derived from the grape. Ferm entation vinegar is distinguishable from artificial vinegar by the iodine value, which is about 3 8 -6 ^ 1 0 % for the former and about 2 for the latter, and by the luminescence of the former when exposed to ultra-violet light. Marc vinegar differs from genuine wine vinegar in having a lower alcohol + acetic acid content, a lower extract, a lower ash, and a less pronounced alkalinity of the ash. Marc vinegars may be distinguished from diluted wine vinegars by their higher ash content, by the higher alkalinity of the ash, by the greater value of the ratio betwreen ash and extract, and by the lower content of alcohol + acetic acid in relation to the fixed acidity. Methods for detecting artificial coloration of vinegars are discussed.

Addition of strong mineral acid to vinegar may be detected by colorimetric determination of the pit value, using thymol-blue as indicator. W ith alcohol vinegar, the p s is diminished from 2-4 to 1-8 or 1-2 by the presence of 0-1 or 0-2% of sulphuric acid, and th a t of wine vinegar is similarly lowered from 2-4 to 2-2, or 2-0, or 1-8 by the presence of 0-1, 0-2, or 0-5% of the

acid. T. H . Po pe.

Pa t e n t s.

Continuous process for preparing n -b utyl alcohol and acetone b y ferm entation. Commercial

Solvents Co r p. (B.P. 306,138, 11.2.29. U .S ., 17.2.28).

—Sterile mash is introduced into the first of a number of fermenters which are connected in series and are preferably located on descending levels. After inocula­

tion of the mash with a butyl alcohol-acetone bacillus, further additions of sterile mash to the first fermenter cause the partially fermented mash to flow from the first fermenter through the others until all are filled.

The influx of fermenting mash is prevented in the last fermenter, and a definite proportion of the mash therein is removed. Fresh sterile mash equivalent in volume to th a t withdrawn is then added to the first fermenter.

C. RaNKEN.

P roduction of acetone and butyl alcohol by ferm entation. 6 . W. Fr e ib e r g (U.S.P. 1,744,958, 28.1.30. Appl., 14.4.27).—After the separation and recovery of the germ portion of steeped maize grain, the residual wet carbohydrate-containing portion of the grain is mashed and subsequently fermented by

micro-organisms. C. Ra n k e n.

M anufacture of baking yea st. H. Cla a sse n

(U.S.P. 1,774,546, 2.9.30. Appl., 6.10.27. Ger., 19.11.26).

—See B.P. 280,861; B., 1928, 686.

XIX.— FOODS.

D eterm ination of cream of tartar and tartaric acid in tartrate baking pow ders. B. G. Ha r tm a n n

(J. Assoc. Off. Agric. Chem.; 1930, 13, 385—389).—To 2-5 g. of baking powder are added 100 c.c. of distilled water a t 50°. After keeping for 30 min. with occasional shaking the solution is diluted to 250 c.c. and filtered.

Two 100-c.c. portions of filtrate are each evaporated to 20 c.c. To one portion are added 3-5 c.c. of A^-potass- ium hydroxide, 2 c.c. of glacial acetic acid, and 80 c.c.

of 95% alcohol. The second portion is treated similarly

except th a t sodium hydroxide is substituted for the potassium compound. The two solutions are placed in a refrigerator for 1 hr., stirred vigorously, and allowed to remain in the refrigerator overnight. The precipitates are collected in Gooch cruciblcs, washed first with ice-cold 80% alcohol and finally with cold alcohol, treated with hot water, and titrated with 0 • liV-alkali, using phenolphthalein as indicator. Then to tal tartaric acid (% )= !• 5A ; cream of ta rta r (%) =1-88-5; tartaric acid ( % ) 1 -5(A—B), where A — titration of portion treated with potash and B th a t with soda. Free ta r­

taric acid may be determined directly by extracting 1 -25 g. of baking powder with 50 c.c. of chloroform in a 200-c.c. graduated flask for 5 min. 100 C.c. of alcohol saturated with cream of ta rta r (free from tartaric acid) are added. After 30 min. the liquid is diluted to 200 c.c.

with alcohol, shaken, filtered, and 100 c.c. of the filtrate are titrated with 0 -liV-alkali, using phenolphthalein.

Tartaric acid (%) = l'-2 X alkali consumption.

A. G. Po l l a r d. L im its of error of the Babcock test for cream . W. H. Ma r t in, A. C. Fa y, and K. M. Re n n e r (J.

Agric. Res., 1930, 41, 147—159).—The results of single tests on 37-—40% cream were not closer than ¿ 0 - 4 4 to

± 0 -5 5 % of fat, nor the averages of duplicates than iO -3 1 to ± 0 -3 9 % of fat. A. G. Po lla r d.

C rystallisation of lactose in sw eetened con ­ densed m ilk . B. Se g a l (J. S. Afr. Chem. Inst., 1930, 13, 33—40).—The texture of sweetened condensed milk is a function of the size of the lactose crystals. The cooling of condensed milk during manufacture should aim at the immediate production of a large number of crystal nuclei rather than the growth of crystals round a small number of centres. A. G. Po l l a r d.

Pure butters and butters adulterated [w ith coconut oil]. L. Hoton (Ann. Falsif., 1930, 23, 324—

337).—The difficulties of detecting adulteration of b utter with coconut oil, even to the extent of 20%, are emphasised. The Polenske determination is con­

sidered to be of little value, and the variability of the results according to the conditions, character of the distillation, etc. is illustrated. Pure butters have given the same ratio of insoluble to soluble fa tty acids as those containing 20% of coconut oil. The differences in the solubilities in dilute alcohol of the fa tty acids in butter, coconut oil, and margarine are also valueless.

The observation that, when heated, the fa tty acids in butter increase in weight owing to oxidation, whilst those in coconut oil lose weight by volatilisation, has been shown to be incorrect. Using samples of pure butter and butter containing 20% of coconut oil, it was found th a t loss of weight occurred in both cases, accompanied

The observation that, when heated, the fa tty acids in butter increase in weight owing to oxidation, whilst those in coconut oil lose weight by volatilisation, has been shown to be incorrect. Using samples of pure butter and butter containing 20% of coconut oil, it was found th a t loss of weight occurred in both cases, accompanied