Sam pling tanning m aterials and extracts. A.
Tu r n b u l l (J. Soc. Leather Trades’ Chem., 1931, 15, 438—440).—Details are given for sampling liquid, solid, and pasty extracts, respectively, and also for sumac. Sampling tools are described and illustrated.
D. Wo o d r o f f e.
Precipitation of [vegetable] tannin by hexa- m ethylenetetram ine in aqueous solutions. A. T.
Ho u g h (J. Soc. Leather Trades’ Chem., 1931, 15, 406—411).—Max. precipitation was obtained at pu 5-6, but no ppt. was given in dil. solutions. The amount of ppt. was increased by the presence of metallic salts, and the following reagent is proposed: 10 c.c.
each of 30% solutions of Zn(OAc)2, NH40Ac, and hexa- methylenetetramine, and 1 c.c. of glacial AcOH. With this reagent 1 pt. of tannin in 200,000 pts. of H 20 yields a ppt. visible to the naked eye, and 1 pt. of tannin in 106 pts. of H 20 a turbidity detectable by the Tyndall
effect. D. Wo o d r o f f e.
Preparation of furfuraldehyde from extracted oak bark from tanneries and other pentosan- containing substances. D. I. Mi r l i s (J. Chem. Ind.
Russ., 1931,8, 697—703).—Extracted tannery oak bark waste or other pentosan-containing substance (maize cobs, sunflower-seed husks, etc.) is autoclaved for
| hr. at 158—160°/6—7 atm. with 5—7 pts. of 1%
H 2S 0 4 and 4% NaCl solution, and furfuraldehyde is immediately distilled off (6—7 atm.). The distillate, containing also AcOH, MeOH, and HC1, is neutralised with Ca(OH)2, and the constituents are separated by fractionation. The process is completed within 3-3—5 hr., the yields of furfuraldehyde being 9-4—10-2%
on the wt. of extracted oak or sunflower husks, or 18%
on the wt. of corn-cobs taken ; 3% of AcOH and 1%
of MeOH are also recovered. Using H 20 in place of the acid mixture in the above process, 6-5—7-0%
yields of furfuraldehyde are obtained. The residue in the autoclave is, as a result of its low acidity, an excellent fuel. R. Tr u s z k o w s k i.
Furfural[dehyde] number of tanning extracts and their m ixtu res w ith sulphite-cellulose extract.
V. N em ec (J. Soc. Leather Trades’ Chem., 1931, 1 5 ,
440—443).—Lauffmann’s method ( B ., 1919, 379 a ) of determining this value has been modified to give more concordant results. A higher figure was obtained for both sulpliited and unsulphited quebracho extracts than for mangrove extract, so th a t the furfuraldehyde no. of quebracho extracts is lowered by admixture with mangrove. The furfuraldehyde no. was lowered pro
portionately to the amount of sulphite-cellulose extract added to a tanning extract. D. W o o d r o f f e .
Fixation of [vegetable] tannin in leather and modification of its characteristics. A. T. H o u g h
(J. Soc. Leather Trades’ Chem., 1931, 1 5 , 411—415).—
The unfixed tannin in a vegetable-tanned leather can be fixed by treating the leather with solutions of hexamethylenetetramine. The analytical figures for such treated leathers are thereby altered : the H 20-sol.
m atter is considerably reduced, the N figure increased, and the apparent degree of tannage is diminished.
D. Wo o d r o f f e.
D iscoloration and staining of leather by copper im purities in vegetable tan liquors. M. P . B a l f e
and II. P h i l l i p s (J. Soc. Leather Trades’ Chem., 1931,
1 5 , 444—454).—Greenish stains on vegetable-tanned
leather may be caused by the reaction of Cu in the suspender liquors with H 2S in the delimed pelts. Cu is an impurity more frequently found in chestnut extracts. The grain of the delimed pelts should be freed from H 2S by aeration of the deliming liquors or by oxidation of the H 2S with H 20 2. Methods are suggested for the determination of H 2S in the leather, delimed pelt, deliming liquors, and suspender liquors.
D. Wo o d r o f f e.
D ensity of leather. U. J. T h u a u and A. G. d e B u d a (J. Soc. Leather Trades’ Chem., 1931, 1 5 , 415—
426).—A simple densimeter is described for determining the real density of leather. The apparent density of a leather was found to exceed th at of any of the four layers into which it was afterwards cut.
D. Wo o d r o f f e.
N a4Fe(CN)?.—See VII. E gg-yolk.—See XIX.
Sewage and industrial w astes.—See X X III.
XVI.— AGRICULTURE.
Fertile soil. VI. A. J. J. V a n d e V e l d e , A. V e r b e l e n ,
and L. D e K o k e r (Natuurwetensch. Tijds., 1931, 1 3 ,
239—246 ; cf. B ., 1931, 556).:—The influence of CaC03 (NH4)2S 04, IvNOj, CaCNo, and superphosphates on the Pn and adsorptive capacity for different dyes of a variety of soils has been examined. The salts have no influence on the adsorption of methylene-blue, but that of methyl-violet is depressed by the Ca salts and increased by (NH4)2S 04 and K N 03 ; th at of methylene-green is
B r itis h C h e m ic a l A b s tr a c ts —B .
Cl. XVI.—Ag r i c u l t u r e. 987
increased considerably by CaC03 and CaCN2. Addition of K halides and variations of the humidity do not alter the adsorptive powers of the soils. H . F. Gi l l b e.
Causes of changes in the adsorptive capacity and dispersion of so ils. M. A. Vin o k u r o v and V. I.
Ka r a b iz k i (Arb. sibirisch Inst. Land- u. Forstw., 1929, 13, 27—51 ; Bied. Zentr., 1931, 60, 293—294).—
The adsorptive capacity of black earths, podsols, and saline soils is not of const, magnitude. Variations are induced by soil reaction and other factors. In columnar saline soils the pn is influenced by the moisture content and the proportion of dispersible humate and zeolite in the adsorptive complex. In black earths and podsols the p n varies with the concentration of the soil solution.
In cultivated black earths and possibly in all cultivated soils there is an inverse relationship between the pa of the soil solution and the activity of the nitrification process. Dispersion varies throughout the vegetative season, being least in summer and greatest in spring and autumn. The degree of dispersion of soils is closely related to the moisture content, concentration of the soil solution, reaction, and adsorptive capacity.
A . G . Po l l a r d.
N eubauer’s chem ico-physiological method for determining assim ilable phosphoric acid and potash in soils. I. C. An t o n ia n i and M. Ni c o l i n i
(Giorn. Chim. Ind. Appl., 1931, 13, 369—372).—Rye seedlings are grown according to Neubauer’s method.
In the ash of the plants K 20 and P 20 5 are determined by the K,PtCl6 method and the strychnine phospho- molybdate method respectively. The average differences in the duplicates were for P 20 5, ± 0 -2 6 (161 duplicate determinations); for K 20, ± 0 -6 5 (151 duplicates).
0. F. Lu b a t t i.
Retention of phosphoric acid by soil organic m atter. G. Ba l a n e s c o (Ann. Sci. Agron., 1930, 47, [3]; P ro c.. Internat. Soc. Soil Sci., 1931, 4, 59).—
Purified humus does not absorb P 0 4" ' from phosphate solutions, whatever their pa- The apparent fixation of P 0 4'" by humus is due to the action of adsorbed cations, notably F e " . The fixation of P 0 4" ' by humus containing Ca occurs only when conditions permit the existence of a phosphate of Ca in the solid phase.
A . G . Po l l a r d.
Transition of water-soluble phosphates in soils.
M. Ge r l a c h (Superphosphat, 1931, 7, 130—133).—The interaction of I I 20-sol. phosphates and soil is discussed, together with the mechanism of the P assimilation of
plants. A . G . Po l l a r d.
Distribution of assim ilable phosphate in soils resulting from the action of growth factors. L.
Dw o r a k (Kiserlet. K o z l., 1 9 3 0 , 3 3 , 3 3 6 ; Bied. Zentr.,
1 9 3 1 ,60, 2 94—2 9 5 ).—The distribution in soils of artifici
ally applied phosphates varies with soil type. In a sandy soil containing CaC03, but deficient in P, the greatest accumulation of easily-sol. P occurred in the horizon from 10 to 3 0 cm. deep. The action of various growth factors does not result in a fixation of P in these soils. In a CaO-deficient soil containing adequate P, fertilisers did not penetrate deeply, although oats assimilated most P from subsurface layers.
A . G. Po l l a r d.
Course of the nutrient intake [of plants] and fertiliser requirem ents. T. R e m y and E. D e i c h m a n n
(Ernähr. Pflanze, 1 9 3 1 , 2 7 , 3 0 1 — 3 1 7 ).—The effects of the nature, quantity, and time of application of fertilisers on the rate of nutrient intake by a number of crops in various stages of growth, and on the distribution of mineral m atter in the plants, is recorded.
A. G. Po l l a r d.
Regularity of plant growth, with special refer
ence to nutritional problem s. A. R i p p e l (Ernähr.
Pflanze, 1 931, 2 7 , 251—2 5 3 ).—The theoretical basis of Mitscberlich’s growth curves is unsound, although the method of determining fertiliser requirements gives valuable practical information. Growth curves obtained with a series of increasing applications of N reach points of max. yield at periods which increase with the N dosage.
Results based on these curves depend therefore on the length of the experimental period and on other soil
conditions. A. G. P o l l a r d .
“ Effect law ’ * of growth factors. E. A. M i t s c h e r l i c h (Ernähr. Pflanze, 1 9 3 1 ,2 7 , 277— 2 8 6 ).—A discussion of the author’s work and a comparison with other methods for determining the nutrient condition of soils
are given. A. G. P o l l a r d .
Effect of gypsum on the assim ilability of the phosphoric acid of phosphorites. A. G. M i c h a l o v s k i
(Düng. u. Ernte, 1 9 3 0 , 9 9 — 1 0 2 ; Bied. Zentr., 1 93 1 , 60,
3 18—3 1 9 ).—Supplementary manuring with S or gypsum accelerated the transition of the P of phosphorites into an easily-sol. form. A. G. P o l l a r d .
Effect of peat on the utilisation of the phosphoric acid of phosphorites. S. V. L o g v i n o v (Düng. u.
Ernte, 1 9 2 9 , 211— 2 1 6 ; Bied. Zentr., 193 1 , 60, 3 1 9 — 3 2 0 ).—Applications of acid sphagnum peat favoured the conversion of phosphorites into CaHP04 or Ca(H2P 0 4)2 in soils. Podsolised soils have a similar action. All types of peat are not equally effective. A. G. P o l l a r d .
Nitrogen econom y of forest soils w here litter is removed. A. N em ec (Forst. Centralbl., 1 9 3 1 , 53,
49— 6 7 , 147— 1 5 6 ; Bied. Zentr., 1 9 3 1 , 60, 2 9 6 ).—
Continual raking off of the litter lowers the total N and nitrate content of the humus and upper mineral layers of forest soils. The height and diam. of the trees and the N content of the needles are correspondingly reduced.
A. G. Po l l a r d.
Conversion of urea in so ils. J. B o r d a s and G.
M a t h i e u (Ann. Sci. Agron., 1 9 3 0 , 1 7 , 7 1 1—727 ; Bied.
Zentr., 1 931, 6 0 , 3 0 0—3 0 1 ).—The decomp, of urea in soil is a biological process and depends on the temp, and the amount of org. m atter present. Addition to soil of (NH4)2S 0 4 or urea and urease accelerates the decomp, of org. matter. In soils containing nitrate and/or nitrite a slow decomp. of urea may result in losses of N. Urea in soil is not completely converted into (NH4)2C03, other org. N compounds being formed.
Nitrification of urea is complete in 5—6 weeks.
A. G. Po l l a r d.
U se of industrial w astes as fertilisers. V. P . M o s s o l o v (Düng. u. Ernte, 1 9 3 0 ,1 8 2—1 8 6 ; Bied. Zentr.,
1 9 3 1 ,6 0 , 3 2 0 ).—Field trials are quoted to show the value of various classes of slaughterhouse wastes as fertilisers.
A. G. Po l l a r d.
B r itis h C h em ica l A b s tr a c ts —B .
988 Cl. XVI.— Ag k i c ü l t u b e.
Twenty years of rotation and manuring experi
m ents. G. St e w a r t and D. W. Pi t t m a n (Utah Agric.
Exp. Sta. Bull., 1931, No. 228, 31 pp.).—Field trials are recorded in which soil fertility was maintained at a high level by the efficient application of farmyard manure only, and by suitable systems of rotation.
A. G. Po l l a r d.
Christensen and Jensen’s work on the effects of m anuring on soils in continuous fertiliser trials.
Op it z (Superphosphat, 1 9 3 1 , 7 , 1 3 6 — 14 0 ).—Results' from continuous manurial trials in various parts of the world are examined. Prolonged use of cattle manure leads to a small but definite increase in the humus con
tent of soils. The leaching out of N from such soils is considerable. With regular and excessive applications of superphosphate there is an accumulation of P in soil, largely in a form easily assimilable by plants. No general relationships exist between the K content of soils and the amounts of K supplied in fertilisers. A. G. P o l l a r d .
Composition of the adsorptive com plex of arid soils as a basis for determ ining salt injury, and potash m anuring in the arid tropics and sub
tropics. P. Va g e l e r (Ernähr. Pflanze, 1930, 26 , 393—
394, 412—414, 440—442 ; Bied. Zentr., 1931, 60, 291—
292).—Salt injury cannot be associated with any parti
cular base or salt content of soils, but is closely related to the ratio of alkali present to the total adsorptive capacity. The ease of removal of salinity can be deter
mined from the differential quotients of the capillarity equation. Sudan soils contain relatively small propor
tions of assimilable K and respond to heavy dressings of K fertilisers. Small applications are non-effective.
A. G. Po l l a r d.
Physico-chem ical changes in arable soils caused by applications of dung. P. A. Vl a s s j u k (Arb.
Versuchs-Stat. Uman, 1930, 10, 93 ; Bied. Zentr., 1931, 60 , 299—300).—The H 20-supplying power of soils was increased in dry seasons by applications of stall manure.
In wet seasons no effect was observed. No relationship exists between the improved H 20 condition and the amount of manure applied. The nitrate and H 20-sol.
P contents of soils iii wet seasons were increased by manuring and the tended to decrease. During the decomp, of the manure there was an increase in the proportion of aggregate soil particles of more than 7 mm.
diam. at the expense of those of 25 [i.—1 mm. diam., without material change in the finest particles. This aggregating effect was smaller than th at produced by liming. The apparent sp. gr. of soil to a depth of 50—
70 cm. increased with the amount of manure added, but the ultimate mechanical analysis of the soil was un
changed. Manuring reduced the proportion of adsorbed Na and K and increased th at of Ca and Mg.
A. G. Po l l a r d.
Manuring of m oors and highlands. M. Po p p
(Ernähr. Pflanze, 1931, 27, 262—265).—In field trials with potatoes, high yields and high starch contents were obtained only by the use of P and K fertilisers. The Cl content of the potatoes increased with the amount of Cl applied in the potash fertilisers. The P 0 4" ' content was increased by the use of potash. The general use of fertilisers did not impair the keeping quality of the tubers, nor influence their value as seed. The ripening
of the potatoes as judged by their amide content was accelerated by applications of K. A. G. Po l l a r d.
Manuring of m eadow s. E. K l a p p (Ernähr. Pflanze,
1 9 3 1 , 15, 3 2 1 — 3 2 9 ).—The effect of manuring on the yield and composition of meadow herbage in Germany is examined and discussed in comparison with average results from other countries. A. G. P o l l a r d .
Principles of green m anuring, and their applica
tion in Ceylon. I. A. W. R. J o a c h i m (Trop. Agric.,
1 9 3 1 , 77, 4— 3 2 ).—The significance of green manuring in the agriculture of Ceylon is discussed. The chemical composition of typical green crops together with their comparative rates of decomp, in soil are recorded. By efficient green manuring satisfactory N and C contents are maintained in soils and their physical condition is
improved. A. G. P o l l a r d .
Is potash manuring necessary ? F. M u n t e r
(Ernähr. Pflanze, 1 931, 15, 33 4 — 3 3 6 ).—Numerous field trials are quoted showing the crop increases obtained by the use of potash fertilisers even when applied in addition to stall manure. A. G. P o l l a r d .
Influence of manuring on the quality of cereals.
E i c h i n g e r (Ernähr. Pflanze, 1 9 3 1 , 15, 3 2 9 — 3 3 2 ).—
Omission of K from fertilisers for rye lowered the hectolitre-wt. of the grain. No significant difference is apparent between the effects of NaN03, Ca(N03)2, and (NH,,)2S04 on the hectolitre-wt. K-deficient fertilisers reduce the proportion of larger grains (by sieving) in the
crop. A. G. P o l l a r d .
Phosphate manuring and storage of cereals.
M . K l e i n (Superphosphat, 1 9 3 1 , 7, 150—1 5 1 ).—The effect of P manures in increasing the stiffness of straw and storage quality of cereals is discussed.
A. G. Po l l a r d.
Manuring and the quality of potatoes. M e y e r - B a h l b u r g (Superphosphat, 1 9 3 1 , 7, 1 5 1 — 1 5 3 ).—Re
commendations for the prevention of scab in potatoes include top dressings with acid fertilisers a t the period of active infection and the liberal use of superphosphate to induce the production of firm-skinned tubers.
A. G. Po l l a r d.
Effect of nutrition on cell size in potato tubers.
G. B r e d e m a n n and W. S c h u l t z e (Ernähr. Pflanze, 1 931,
2 7 ,2 9 3—2 9 5 ).—Applications of potash fertilisers whether in spring or autumn produced tubers with cells of larger diam. No relationship exists between cell size and that of starch grains. Applications of N increased the mean diam. of the cells by reducing the proportion of smaller cells, and, simultaneously, decreased the mean diam. of starch grains by increasing the proportion of small
grains. A. G. P o l l a r d .
Influence of carbon dioxide and of oxygen on the sprouting and value of potato tubers. H.
B r a u n (Arb. biol. Reichanst. Land-u. Forstwirts., 1931,
19, 17—9 3 ).—An artificially increased C02 content of the atm. in storage chambers favoured the sprouting of potato tubers, but in subsequent field trials the crop yields were either unaffected or reduced by this treat
ment. The effect varied with the temp, of storage and the species of potato. Reduction of the 0 2 of the storage atm. reduced the vitality of the tubers. Under
B r itis h C h em ica l A b s tr a c ts —B .
Cl. XVI.— Ag r i c u l t u r e. 0 8 9
similar conditions an increase of C02 favoured, and a reduction of 0 2 retarded, the growth of fungal para
sites. The bearing of this on the result of field experi
ments is discussed. A. G. P o l l a r d . jig Q u a l i t y a n d c o m p o s i t i o n o f p o t a t o e s , w i t h s p e c i a l r e f e r e n c e t o t h e a s h a n d p o t a s h c o n t e n t s o f t h e t u b e r s . Ge y e r (Ernähr. Pflanze, 1931, 2 7 ,
286—293).—Potatoes grown on light soils have higher ash and K contents than those grown on heavy soils, although the relative magnitude of these values remains practically the same for the same varieties grown on different soils. Varieties with high ash contents usually have high K contents. There is no relationship between the condition and health of the plants and their ash and K contents. A. G . P o l l a r d .
Rate of nitrogen intake from am m onium salts and nitrates b y agricultural crop plants. K . S c h m id
(Diss., L. H., Hohenheim, 1930; Bied. Zentr., 1931, 6 0 ,
309).—Maize, barley, and wheat plants were able to withdraw NH4‘ and N 03' more easily from very dil.
solutions (0-0005N), the NIL, being the more rapidly absorbed. The effects, on the rate of assimilation, of the concentration and reaction of the nutrient, temp., light, and age of the plant are examined.
A. G. Po l l a r d.
W ater-supplying power of the soil under different species of grass and w ith different rates of water application. P. A. We l t o n and J. D. Wil s o n (Plant Physiol., 1931, 6 , 485—493).—The H 20-supplying power of soil under grass, as determined by the porous-porcelain soil point, varies with the type of grass. A narrow
leaved grass (fescue) imposed a smaller demand on avail
able soil moisture than did the broad-leaved types
oxamined. A. G. Po l l a r d.
H-ion concentration of soil and its relation to