C. A. Kl e in and R. S. Brow n (E.P. 278,791, 8.7.26).
—Barium carbonate is added to the boiling water into which a paste of barium and titanium sulphate is to be poured (cf. E.P. 243,081 ; B ., 1926, 99). The sulphuric acid liberated on the hydrolysis of the titanium sulphate, hitherto waste, reacts with the carbonate. The addition of hydrochloric acid or other acids capable of yielding soluble barium salts which are decomposed by sul
phuric acid is also claimed. S. S. Woolf. Manufacture of lacquers etc. I. G. Fa r b e n in d. A.-G. (E.P. 262,818,13.12.26. Ger., 14.12.25).—Lacquers are obtained by treating condensation products of carb
amide or its derivatives and formaldehyde, preferably in an organic solvent, with an equal or greater amount of cellulose esters, resins, cyclic ketones, or other organic substances capable of forming solid solutions with the condensation product. S. S. Woolf.
Organic m oulding com position. S. M. Hu l l, Assr. to We s t e r n Electric Co., In c. (U.S.P. 1,648,719, 8.11.27. Appl., 13.6.24).—A protein is condensed with a substantially anhydrous aldehyde. J. S. G. Thom as.
Manufacture of [phenol-aldehyde] condensation product. M. Mel am id (U.S.P. 1,648,858, 8.11.27.
Appl., 6.5.20. Ger., 27.12.18).—See E.P. 137,291; B ., 1921, 520 a.
Resin from gutta-percha (E.P. 278,922).—SeeXIY.
Solvent for u se in varnishes (E.P. 275,652).—See XX.
X IV .— IN D IA -R U B B E R ; G U TTA -PER C H A . Colloid ch em istry of rubber latices. D eterm ina
tion of actual and potential alkalinity of latex from H evea b r a s ilie n s is . E. A. Ha u s e r and P. Scholz
(Kautschuk, 1927, 304—305).—The electrometric method is unsatisfactory for the measurement of the j)s of
B r i t is h C h e m ic a l A b s t r a c t s —B .
948 Cl. X V . — Lk a t h h b ; Gl u e.
rubber latex, and methods based on the colour change with indicators, particularly Wulff's method employing a film stained with an indicator, are preferable. From the moment of tapping until shortly before coagulation the pn of latex is between 7-2 and 7-0, and then falls to 6-9—6-6. The higher values obtained by earlier workers are attributed to experimental error. The limited range of variation in pn is ascribed to the existence of an equilibrium between hydroxyl ions in the solution and those adsorbed a t the surface of the rubber globules. Determination of the potential alkalinity by titration using bromothymol blue or phenolphthalein as indicator reveals more distinctly a decrease in the alkali content of the latex prior to spontaneous coagula
tion. D. F, Twiss.
H evea latex. VII. Rubber derived from pre
served latex. R. 0 . Bishop (Malayan Agric. J., 1927, 15, 271—282).—Rubber from ammonia-preserved latex vulcanises more rapidly than rubber from fresh la te x ; the difference is even more marked with rubber coagu
lated with alcohol than with rubber coagulated with acetic acid. Investigation of the proportion of amide nitrogen and amino-acids in preserved latex reveals no increase commensurate with the alteration in the rate of vulcanisation. I t is possible th a t the observed changes in vulcanising properties are associated with the presence in latex of a labile complex substance (cf. Belgrave, B., 1924, 265; 1925, 771), which is affected by variation in the hydrogen-ion concentration
of the latex. D. F. Twiss.
Variation in plantation rubber. B. J. Eatonand R. 0. Bishop (Malayan Agric. J., 1927, 15, 283—289).—
Examination of about fifty samples of rubber from various Malayan estates shows th at although the rate of vulcanisation in a rubber 90: sulphur 10 mixture varies very considerably, the tensile properties of the vulcanised product are notably uniform. Of twenty-four samples of smoked sheet rubber nineteen had an optimum period of vulcanisation between 3 and 4 hrs., the normal figure for smoked sheet being 2 J—2J hrs.
D. F. Twiss.
Pa t e n t s.
Concentration of the globuloids in rubber latex.
M. S . Stutc hbury, Assee. of W. Baciimann, F. I Ieb l e r, and C. Bohmv o n Bornegg(G.P. 442,856, 2.10.23).—The concentration of latex by filtration, centrifuging, or evaporation is facilitated by previous treatm ent with an agglutination agent, e.g., a solution of an aluminium salt, with the previous addition, if desired, of substances to prevent coagulation. D. F. Twiss.
D yeing o f india-rubber etc. Metzeler & Co. (E.P.
241,214, 9.10.25. Ger., 9.10.24).—India-rubber, gu tta
percha, and similar substances in solution in organic media or in aqueous suspension are treated with solutions of suitable dyestuffs, e.g., acid, vat, or sulphur dyes, which can subsequently be converted into an insoluble
form. D. F. Twiss.
Manufacture of rubberised m aterial and com po
sitions for sa m e. Ge n. Ru b b e r Co., Assees. of 31. C.
Teague(E.P. 250,167,14,9.25. U.S., 1.4.25).—Materials such as concrete, wood, stone, cork, or various fibrous
materials which are not easily wetted by water are treated with a sulphonated oil (or o-toluidine, sodium sulphanilate, sodium salicylate, thiourea, or ammonium linolenate or ¿solinolenate) and an artificial or natural aqueous dispersion of rubber. The former, which facilitates wetting, may be applied before or together with the rubber emulsion. A suitable proportion of the wetting agent is 5% calculated on the rubber.
The rubber dispersion may contain compounding and
other ingredients. D. F. Twiss.
Accelerating vulcanisation [of rubber]. Sil e sia
Ve r. Chem. Fa b r. (E.P. 270,644,18.2.27. Ger., 4.5.26).—
Vulcanisation of rubber is accelerated by salts of substituted guanidines with inorganic acids, e.g., by di-o-tolylguanidine thiosulphate. D. F . Twiss.
Manufacture of a solid resin from the sem i-fluid resinous m atter extracted from crude gutta-percha and/or balata. A. B . Cr a v e nand Yorkshire Dy ew a r e
& Chem ical Co., Lt d. (E.P. 278,922, 1.1.27).—The semi-fluid resin obtained from gutta-percha and/or balata, e.g., by extraction with cold petroleum spirit, is agitated and treated with a current of air in the presence of a siccative, e.g., 1% of manganese re siu a te; during the oxidation process the temperature is raised from 60° to 100° by external heating. The resulting solid resin has a pale amber colour and usually contains approximately 3% of free acids. For the purpose of neutralising these 0-5% of quicklime may be added to the liquid resins before oxidation. D . F. Twrss.
Manufacture of finely-divided substances from natural [rubber] em ulsions or suspension s. De
Ba taafsche Petroleum Ma a t sc h a ppij, and F. R. Moser
(E .P . 278,395, 7.4.26. Addn. to E.P. 245,418; B ., 1927, 100).—The process of the prior patent is applied to the coagulation of natural emulsions (e.g., rubber latex).
The latex is coagulated in the presence of finely-divided, colloidal substances such as clay, aluminium hydroxide, silica, etc. which may be produced during the coagulation by suitable chemical reactions. The product obtained,
“ latex gel,” is miscible with all materials used in the manufacture of india-rubber goods, with substances for the preparation of mineral aggregates, with paper pulp for the manufacture of waterproof paper, etc. The gel
¡s much more stable than ordinary or preserved rubber
jatex. R. C. Od a m s.
Vulcanisation process and product. A. C. Burrage
(E.P. 279,280, 4.1.27).—See Can. P. 245,929—30; B., 1926, 453.
X V .— L E A T H E R ; GLUE.
Action of sodium sulphide solutions in the m anufacture of sole leather. V. Ca sa b u r i (Leder- tech. Rundschau, 1927, 19, 105—111, 117—124, 141—
146).—Experiments have been carried out with solutions (d 1-004, 1-007, 1-010, 1-014, and 1-018) of freshly- prepared sodium sulphide, commercial sodium sulphide (alone and with sodium chloride), ammonium chloride, and calcium chloride, respectively, on dried hides.
The hydroxyl and hydrosulphide ions absorbed by the hides increased as the strength of the solutions increased, and in the latter case proportionally. The results obtained were better in every case than
B r i t is h C h e m ic a l A b s t r a c t s — B .
C l. X V I.—Ag r i c u l t u r e. Ö40
with lime alone. A solution of sodium sulphide (d 1-0105) containing sodium chloride gave the best yield and quality of leather, and prepared the pelt for tanning. The use of sodium salts prevents the precipitation of the tannin by lime in the pelt. The function of deliming is not to remove the lime bu t to provide a thin, acid pelt layer between the alkaline pelt and the tannin, until the tannin and pelt have combined. This layer should always precede the penetration of the tannin. The acid is not for swelling but as an aid to tannage. The strength of the tan liquors is unimportant if a suitable amount of acid is present. The collagen fibres are not split up into fibrils by alkaline swelling, but the membrane encasing the collagen fibre becomes elastic and stretches to its maximum length as the swelling increases. Acid swelling splits up the collagen fibre into fibrils, con
sequently the leather produced is soft and fallen. The pelt should be in an alkaline swollen condition a t the moment of the fixation of the ta n n in ; there must therefore be an acid intermediary layer on both surfaces of the leather a t 5-0 (approx.). D. Woodroffe.
Welted insole leather. H. Br a dley and A. Colin- Russ (J. Soc. Leather Trades’ Chem., 1927, 11, 329—
336).—Different samples (51) of vegetable-tanned insole leathers were analysed for moisture, fat, water-soluble m atter (official), free tannin, ashed water-soluble matter, ashed insoluble matter, fixed tannin, degree of tannage, density, and true water-soluble m atter. The water- soluble m atter per unit of hide substance was calculated from the results, and the leathers are divided into three groups : (a) hide substance > 38% , (b) 3S—30%, and (c)
<[30%. The higher the hide substance, the lower was the value of the water-soluble m atter per unit of hide substance; e.g., < 0 -5 , 0-5 to 0-9, and > 0 -9 , respec
tively, for the above hide substance groups. The other analytical figures for leathers in these respective groups show th a t the latter are groups of quality. Leathers which have caused staining of hose are to be found amongst those in the third (or possibly the second) group. Insole leathers should be analysed by the official methods and graded according to the content of hide substance.
The values for ash, fat, and ratio of free tannin to water- soluble m atter in the respective groups a r e : (a) 2-5%, 2-0%, 0 -7 ; (b) 3-5% , 4-0% , 0 -6 ; (c) 5-0% , 4-5%,
0-5. D. Woodroffe.
Extraction of tannins and w ater-soluble [m atter]
in leather an alysis. J. Ch arter s (J. Soc. Leather Trades’ Chem., 1927, 11, 350—351).—The neck of an inverted, wide-mouthed bottle, from which the bottom has been cut off, is fitted with a cork through which passes a small-bore capillary tube bent back on itself to form a siphon, the latter being covered by a test tube to prevent clogging. A flask (1 litre or larger) is used as a reservoir above the bottle and is fitted with a two-hole cork, through which pass an air vent and a long glass tube bent twice a t right angles, which is connected by a rubber tube and screw clip to another glass tube delivering water from the flask into the bottle. The leather to be extracted is placed in the inverted bottle, covered with water to below the siphon, kept over
night, and water allowed to run in drop by drop.
The rate of flow and the temperature of the water are regulated, and the extraction is intermittent.
D. Woodroffe. U tility and solvent action of different fat solvents in the determ ination of fat in leather. R. La u f f-
m an n(Ledertech. Rundschau, 1927, 19, 63—65, 71—74).
—The solvent action of fats and oils in leather is diminished by their formation of compounds with the hide substance or of calcium, magnesium, and chromium soaps. Certain non-fatty substances, e.g., tannins, sulphur, are dissolved by fat solvents, their solubility being increased by the presence of moisture. Samples of leather were treated with weighed amounts of degras and Turkey-red oil, respectively, and the dry leather was extracted after 2 and 120 days with solvents such as carbon disulphide, chloroform, ethyl ether, light petrol
eum, and carbon tetrachloride. The amount of fat extract was less in every case than the calculated;
the amounts of natural grease extracted varied from 1 ■ 6% with light petroleum to 2 ■ 4% with ether. Chloro
form and carbon disulphide yielded the most extract.
The author does uot agree with Woodroffe’s explanation of the increased amount of extract from damp leather (cf. B ., 1924, 529). The low yield of extract from leather fat-liquored with Turkey-red oil is attributed to the soap present in it and to the partial insolubility of the sulphonated constituents. D. Woodroffe.
Pa t e n t s.
Tanning of shark skins. A. Eh ren reic h (E .P . 278,885, 14.10.26).—Shark skins are tanned, the dermic dentelli are removed, and the skins arc given a supple
mentary tanning or “ super-tanning ” by any known
process. D. Woodroffe.
D issolution and reprecipitation of collagen or glutin. M. Ber g m a n n and H. Ko ester (G.P. 442,520, 1.2.25).—Collagen or glutin, or materials containing them, are extracted separately in a definite order or together with solutions of metal ammines, e.g., cupram- monium hydroxide. The solutions may, if desired, be mixed with metal ammine solutions of other substances, of vegetable or animal origin. The final product is precipitated with acids or other substances capable of decomposing the metal ammine compound. Threads can be prepared by forcing the solutions of collagen and/or glutin through fine orifices into a sulphuric acid precipitation bath. D. Woodroffe.
Production of sw ollen or liquid anim al glue.
W. von Rechenberg (G.P. 442,046, 29.10.25).—Car
bonates, which neutralise acids formed by oxidation with liberation of carbon dioxide, are added to the glue in addition to the usual preservatives. L. A. Co les.
Solvent for u se in shoe-cream s (E.P. 275,652).—See XX.
X V I — A G R IC U LTU R E.
N itrates and w heat yields after certain crops.
P. E. Ka r r a k e r (Soil Sci., 1927, 24, 247—258).—The percentages of nitrates in soil samples from plots cropped under different rotations have been determined. The experiments extended over 5 years, the samples being taken in the autumn when wheat was sown. The
B r i t i s h C h e m ic a l A b s t r a c t s —B .
950 C l. X V I.— Aq u i c u l t u r e.
figures lor tlie last 3 years indicate a fairly close relation between nitrate production and wheat yields ; over the whole period the relationship is only very general.
C. T. Gim in g h a m. Effects of lim in g and green m anuring on crop yields and on soil supplies of nitrogen and hum us.
C. A. Mooers (Tenu. Agric. Exp. Sta. Bull., 1926, No. 135, 64 pp.).—The principal effect of liming, in rotation of cowpeas with wheat, was to increase the am ount of available soil nitrogen. Such stimulation accords with the law of diminishing returns.
Ch e m ic a l Ab s t r a c t s.
Variable occurrence of nitrates in so ils. P. E.
K a r r a k e r (Soil Sci., 1927, 24, 259—262).—Large varia
tions in the amounts of nitrogen as nitrates in individual samples of soil from apparently uniform plots are re
ported. C. T. Gim in gh am.
N itrogen lo sses through deutrification [in so ils].
A. M. Bu s w e l l and S. L. Ne a v e (Soil Sci., 1927, 24, 285—290).—A summary of recent literature on the subject, with bibliography. C. T. Gim in gh am.
[Yield from ] barley of different nitrogen content.
An o n. (J. Dep. Lands Agric. Ireland, 1927, 26 , 333—
334).—Apparently poor seed containing 1-8% N gave slightly better crops than apparently good seed (of the same stock) containing 1-25% N.
Chem ical Abstr a c t s. Effect of hydrogen-ion concentration on absorp
tion of phosphorus and potassium b y w heat seed
lin g s. J. Dav idso n (J. Agric. Res., 1927, 35, 335—
346 ; ef. Davidson and Wherry, B., 1924, 484).—Wheat seedlings grown in potassium phosphate solutions absorbed relatively more potassium than phosphorus.
In solutions with initialp n 5-0 or lower, this preferential absorption of potassium resulted in increased acidity, and more phosphorus was absorbed from these solutions than from those of pu 6 ’0 or 7-0. The physiological availability of phosphorus thus appears to depend on the p h value of the medium. The excess of phosphorus absorbed from the acid solutions was found in the tops of the seedlings. The roots from the neutral solutions contained more phosphorus and almost twice as much potassium as those from corresponding acid solutions.
Absorption phenomena of this type may be explained by the assumption th a t there is a relatively wide range in the isoelectric points of the individual protoplasmic ampholytes of the cells. C. T. Gim ingham.
Reactions between m onocalcium phosphate and s o ils. R. H. Au s t in (Soil Sci., 1927, 24, 263—269).—
Titration of monocalcium phosphate with calcium oxide leads to the formation of tricalcium phosphate and calcium monohydrogen phosphate ; with calcium carbonate the latter only is formed. The view th a t aluminium renders phosphorus highly insoluble in an acid soil medium is not confirmed, since little aluminium phosphate is formed when monocaleium phosphate is titrated with aluminium hydroxide. In general, a change from acid to alkaline reaction is accompanied by a rapid decrease in the phosphorus in solution ; never
theless the soluble phosphorus may be extremely low in some very acid soils, indicating th a t some factors other
than soil reaction or the content of iron and aluminium determine its amount. C. T. Gim in g h a m.
Production of available phosphates from Isu m e phosphorite. I. G. Ro sh d est v e n sk i (Ukraine Chem.
J., 1926, 2, 179—194).—In order to convert the phos
phoric acid present in Isume phosphorite into a form easily assimilable by a method other than conversion into a superphosphate, the m aterial was treated with portions of a solution of 1% sulphuric acid and AMiydro- chloric acid. I t was found th a t lime was extracted each time, first in smaller, then in larger quantities;
phosphoric acid was similarly extracted, the amount present in each extraction depending on the concen
trations of sulphuric acid. F urther replacement of the hydrochloric acid by various salts (e.g., sodium, potassium, or magnesium chlorides) showed th a t the amount of lime extracted depended on the nature of the salt used in the solvent. Vegetational experiments in
dicated th a t treatm ent of the phosphorite with a mixture containing 0 • 5Ar-sulphuric acid, 0 • 15AT-sodium chloride, and 0- lAr-magnesium chloride gave the best increase (36-6%) in the crop of barley. A. Ra t c l if f e.
M utual effects between plant grow th and the change of reaction of the nutrient solution w ith am m onium sa lts a s the source of nitrogen. T. L.
Loo (Japan. J. Bot., 1927, 3 , 163—203).—Knop’s solu
tion was modified by the use of sodium nitrate and inorganic ammonium salts instead of calcium nitrate as the source of nitrogen. In contact with the roots, the solution containing ammonium nitrate, chloride, or sulphate becomes more acid, th a t of ammonium hydrogen phosphate or carbonate changes little, whilst th a t containing sodium nitrate becomes less acid except for buckwheat, horse-bean, and lupins. The inferiority of ammonium salts as the source of nitrogen for higher plants is ascribed to the increase in hydrogen-ion con
centration of the solution during g row th; addition of sodium phosphate or calcium chloride to ammonium chloride or sulphate is beneficent, as it retards the rise of acidity. Chem ical Abstra cts.
Buffer capacity of so ils and its relation to the developm ent of so il acidity from the u se of am m on ium sulphate. W. H. Pie r r e (J. Amer. Soc. Agron., 1927,19, 332—351).—A collodion-sac method of obtain
ing the soil extract is described. In greenhouse experi
ments (supported by field experiments) the use of 500 lb.
of ammonium sulphate per acre caused the acidity of two of fourteen soils to exceed p u 4 -8 ; 1000 lb. per acre caused six soils to reach this or a lower value.
Chem ical Ab st r a c t s. R elativity of the term s “ alkalinity ” and
“ acidity ” as applied to so ils. J. Cl a r e n s (Bull.
Soc. chim., 1927, [iv], 41, 1383—1387 ; cf. B., 1926, 762).—In the presence of other salts, e.g., sodium, calcium, or ammonium chlorides, the results obtained for the alkalinity of soils by the method previously described are modified considerably owing to adsorption of salts by the soil or to replacement of some of the soil base by the metal in solution. Sodium salts generally make the soil appear to be more alkaline, and calcium and ammonium salts more acid than it really is.
A . R. Pow ell.
B r i t is h C h e m ic a l A b s t r a c t s — B .
Cl. X V I.— Ag r i c u l t u r e. Ö51
Percentage of carbon dioxide in soil a ir . C. 0.
Appl e m a n (Soil Sci., 1927, 24, 211—245).—Analyses of the soil air in rows of potatoes in the presence of different amounts of organic m atter are recorded. Incorporation of organic m atter increased the percentage of carbon dioxide in the soil, the increase being greatest under wet weather conditions, permitting only poor aeration.
On the day following cultivation after a period of wet weather, the am ount of carbon dioxide in the soil air was reduced by over 90%. When the percentage of carbon dioxide in the soil air was a t its highest, analyses of the air 12 in. above the surface showed only the normal content of carbon dioxide. C. T. Gim in g h am.
Chem ical determ inations to be m ade in the course of a so il su rvey. P. L. Gile (J. Amer. Soc. Agron., 1927, 19, 285).—The composition of the colloidal and non-colloidal fractions is more significant than th a t of the whole so il; the mineralogical composition of the non-colloidal material is also important.
Chem ical Abstr a c t s. S oil colloids. M . M . McCo o l (J. Amer. Soc. Agron., 1927,19 , 289—297).—The soil colloids appear to control the chemical and physical reactions and properties of soils. During the weathering process the colloids, on account of their adsorptive capacity, act as protecting
Chem ical Abstr a c t s. S oil colloids. M . M . McCo o l (J. Amer. Soc. Agron., 1927,19 , 289—297).—The soil colloids appear to control the chemical and physical reactions and properties of soils. During the weathering process the colloids, on account of their adsorptive capacity, act as protecting