Oiling of leather. T. G. Rocnow (J. Physical Chem, 1929, 33, 1528—1542).—A soft and pliable leather can be obtained by displacing water from wet cow-hide leather by alcohol and introducing cod oil as a solution in xylene. Untanned skin swollen by water and kept swollen by means of solutions which-removed
it remain flexible on drying when immersed in a xylene solution of oil, whilst skin which is allowed to dry before immersion in oil remains hard and stiff. The function of water in the oiling process appears to lie in the swelling and separation of fibres, so th a t oil can penetrate universally. Cod oil wets leather in preference to water, but the displacement of water by the oil is slow. In general, more surface of oil should be offered to leather fibres in order to increase penetration. Usually the water already present is sufficient to reduce the surface tension of the oil, but with mineral oil this must be accomplished by the addition of suitable substances.
Theories of tanning are discussed. L. S. Th e o b a l d. Pa t e n t s.
Manufacture of artificial [casein] com positions and articles m ade therefrom. J. Y. Jo h n s o n. From I. G. Fa r b e n i n d. A.-G. (B.P. 321,423, 30.6.28).—
Mixtures comprising casein, pigments, e tc , and sub
stances which generate gases a t raised temperatures, e.g., ammonium and sodium bicarbonate, are forced through an extrusion press at a temperature, e.g., 60—70°, such th a t the gases are generated and render the products porous. The products may be dried or hardened, e.g., by treatm ent with formaldehyde.
L. A. Co l e s.
Manufacture of a casein adhesive. E. St e r n
(G.P. 451,308, 6.9.24).—A mixture of dry, powdered cascin and dry starch compounds of the alkaline earths or magnesium is made into a paste with cold water.
A. R. Po w e l l.
Manufacture of dry adhesives soluble in cold water. M. He i m (G .P . 453,501, 25.11.24).—A mixture of 100 pts. of starch, 50 pts. or more of powdered glue, and 50—100 pts. of saturated calcium chloride solution is set aside in a warm place until a dry mass is obtained which can be ground to a powder readily soluble in a small quantity of cold water. A. R. Po w e l l.
T reatm ent o f hides. 0 . Ro h m (U.S.P. 1 ,7 3 5 ,9 7 7 , 1 9 .1 1 .2 9 . A ppl, 5 .2 .2 5 . G er, 1 .4 .2 4 ).—See B.P.
2 3 6 ,4 8 3 ; B , 1 9 2 5 , 7 3 0 .
Chromic com pounds (B.P. 294,965).—See VII.
XYI.—AGRICULTURE.
G eology and m ineralogy of soils. II. Soils of South-East Scotland. R. Ha r t (J. Agric. Sci, 1929,
1 9 , 802—813 ; cf. A , 1929, 289).—Mineralogical
examination of the soils in this area suggests an appreci
able supply of potash, although this may not be readily available, an indefinite amount of phosphate-bearing minerals, chiefly apatite, and a fair proportion of lime- bearing minerals, notably plagioclase, augite, and hornblende. One soil from Innerwick is peculiar in th a t the ferrosilicate minerals are mainly iron oxides, possibly due to continued cultivation with its attendant aeration, and to the use of artificial fertilisers.
E. Ho l m e s.
Com posite character of the soil profile, its relation to soil classification. C. G. T. Mo r is o n
(J. Agric. Sci, 1929,19, 677—683).—A discussion of the modifications in the Russian scheme of soil classification necessary to fit British conditions. Examination of
bb 2
B ritis h C h em ical A b s tr a c ts —B.
72 C l. XVI.—Ag r i c u l t u r e.
soil profiles near Oxford has shown th a t in addition to the A zone, or zone of leaching, and the B zone, or zone of accumulation, there can be distinguished a solubility profile, in which the total content of exchangeable bases is low, but increases in depth, especially in the B horizon ; a skeletal profile, in which iron and aluminium are low in the A horizon, but high in the B ; and an organic profile showing normal vertical distribution in A 0 and A v very low in the rest of A, showing accumulation in the B horizon and normal diminution due to oxidation throughout B. Soil types can then be indicated by the dominance of one profile ; thus in saline and alkaline soils the solubility profile is dominant, in podsol types the humus profile is dominant (e.g., in the north and west of Great Britain), whilst in laterite, skeletal and solubility profiles build up the typical section. The chief agricultural lands of Great Britain are discussed on the basis of these classifications, .¡¿j E. Ho l m e s.
Laws of soil colloidal behaviour. II. Cata- phoresis, flocculation, and dispersion. S. Ma t t s o n
(Soil Sci, 1929, 28, 373—409).—Bentonite and several soil colloids are used in an examination of the phenomena of flocculation and cataphoresis in solutions of various electrolytes. Experimental results do not confirm the theory th a t the particle charge and stability are asso
ciated with an absorption of ions from the added electro
lyte, but tend rather to show their relationship with the degree of dissociation of the exchangeable ions. The proportion and nature of these latter control the osmotic hydration, sensitivity to electrolytes, and dispersibility of the colloid. The size of colloidal particles represents an equilibrium between cohesive and dispersive forces as governed by ionic density. For each particular colloid there is thus a particle size of maximum stability.
Flocculation results from the linldng together of micelles (not of particles) by electrostatic attraction. There is no critical cataphoretical potential at which soil colloids flocculate. Stability is largely controlled by hydration.
The dispersion and size of colloidal particles are intimately connected with the charge they carry, but it is not estab
lished th at the stability of the micelle results from mutual repulsion. The osmotic hydration of the micelle is sufficient to explain the stability of a suspension.
A. G. Po l l a r d.
Microflora of leached alkali so ils. I. Synthetic alkali soil. J. D. Gr e a v e s (Soil Sci, 1929, 28, 341—
346).—An artificial alkali soil was prepared, subse
quently leached with water, and cropped. Leaching resulted in an increase in the number of micro-organisms, notably among the ammonifying, nitrifying, and nitrogen- fixing bacteria. The morphological characteristics of the flora of the leached and cropped soil are recorded.
A. G. Po l l a r d.
Com position of som e T urkish soil-im proving
“ earth s.” F. Gi e s e c k e (J. Landw , 1929, 77, 201—
217).—The efficiency of various “ e a rth s” used in Turkish agriculture as soil improvers depends more on their contents of chalk or marl than on the presence of notable amounts of plant nutrients.
A. G. Po l l a r d.
Nutrient content of T urkish soils. F. Gi e s e c k e
(J. Landw , 1929, 77, 223—250).—Chemical and
me-chanical analysis of numerous soils are recorded.
Generally speaking, these soils are not so highly fertile as earlier work suggests. A. G. Po l l a r d.
O xidation and reduction processes in podsol so ils. N. P. Re m e s o v (Z. Pflanz. D üng, 1929, 15A, 34—44).—Changes in the oxidatioh-reduction potential (Ei,) of soils under various conditions are recorded. A rapid decrease in Eh is associated with the transition from the humus sub-horizon to the podsol horizon, and this becomes still more marked in the illuvial horizon.
Among soils in different stages of peat formation E/, declines as the process advances. Maximum Eh values are attained in early summer. In humus horizons seasonal variations in E/, are greater than in any other sub-horizon. Values of E/t in pasture soils are always greater than those of the same soil under any other treatment. Farmyard manure reduces the Eh of soils, not only by adding organic matter, but also by increasing the numbers of reducing bacterial such as B. coli. Lime increases the Eh of soils when applied alone or with farmyard manure, and such increase is due to improved soil structure and aeration leading to more intense oxidation. A. G. Po l l a r d.
Q u in h y d r o n e - e le c t r o d e a n d i n d i c a t o r m e t h o d s f o r m e a s u r i n g t h e p a o f s o il s ; t h e i r in d iv i d u a l a p p l i c a t i o n a n d c o m p a r i s o n . S . Kü h n (Z. Pflanz.
D üng, 1929, 15A, 13—33).—The use of the quinhydrone electrode with certain soils leads to indefinite p B measure
ments, and the changes in recorded pu values with time are irregular. After removal of all colloidal m atter from aqueous soil extracts by mixing with barium sulphate (“ pro Röntgen ” ) and centrifuging, the recorded p a values show a strong tendency to drift towards the acid area. Carefully recrystallised quin
hydrone in aqueous solution has pn 3-4 approx, and imparts a definite acid reaction to a soil suspension.
The barium sulphate treatm ent did not significantly affect the p a values of soil extracts determined by the indicator method. Aqueous soil extracts are much more weakly buffered than the corresponding soil suspensions. The indicator method is considered far more exact and reliable than the quinhydrone-electrode
method. A. G. Po l l a r d.
Determ ination of the buffer capacity of so ils. B. Ta c k e and T. A u n d [with W. Si e m e r s and W. Ho f f m a n n] (Z. Pflanz. D üng, 1929,15A, 44—51).—
In the application to moor soils of the Jensen method for determining lime requirements, it was found th a t the value of the limed soil, after the specified treatm ent for removing excess of free lime, did not rise above 7-5 however great was the quantity of lime added;
irregularities in the form of the pn-lim c curve for buffer- free sand also appeared. By passing air of normal carbon dioxide content through lime water, an equi
librium condition was produced, after several hours, having 7-4—7-5. The same value was reached when equilibrium was attained by other processes. It is considered th a t Jensen’s aspiration method for removal of excess of free lime prior to determinations of pn values fails to ensure equilibrium between lime, water, and carbon dioxide, and results are correspondingly unreliable. By prolonged aspiration it is shown th at
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. 7 3
both in mineral and moorland soils the true lime titra- tion-/j}j curve intersects the control buffer-free curve in the alkaline area. The buffer-free sand yields a titration curve which, 011 the alkaline side, lies nearer the neutral zone than Jensen suggests.
A. G. Po l l a r d.
Determ ination of the lim e requirem ent of soils on the basis of their hydrolytic acidity. J.
v o n Cr i k y and G. v o n Ep e r j e s s y (Z. Pflanz. Düng, 1929,15A, 5—12).—Well-known methods for determin
ing the lime requirement of soils are compared. Kappen’s process gives satisfactory results when an empirical factor is used to calculate from the hydrolytic acidity the lime required to bring the soil reaction to a definite Pk value. The method is applicable to soils of neutral reaction and considerable “ latent ” acidity to which the Christensen-Jensen method is unsuited. In the Hungarian soils examined the lime requirement, calcu
lated as 5 X hydrolytic acidity (Kutchinsky), agrees with values obtained in the Christensen-Jensen process if the latter is calculated to p a 8-0. The hydrolytic acidity values vary considerably with the ratio soil:
solution used in the determination. Hissink’s value (T — S) as a measure of the lime necessary to neutralise hydrolytic acidity is preferable to those obtained by other adsorption methods. A. G. P o l l a r d .
M echanical an alysis of soils. C. S. Pi p e r and
H . G. Po o l e (Council Sei. Ind. Res. Australia, 1929, Pamphlet No. 13, 19 pp.).—A comparison of methods and results of mechanical soil analysis by the method developed at the Waite Institute and by the Interna
tional method. A description is given of modifications necessary to make the former conform to, and of methods of interpolating results by the Waite method in terms of, International standards. E. Ho l m e s.
Hot ferm entation of m anure in practice. We c k e
(Forts. Landw , 1929, 4, 68 ; Bied. Z entr, 1929, 58, 501—504).—The general practice of the “ making ” of farmyard manure is discussed with special reference to the advantages of the Krantz hot-fermentation process. Apart from the mechanical advantages in stacking and the improved physical condition of the hot-fermented product in handling, field trials show an enhanced fertiliser value. Comparative crop yields with ordinary yard manure and hot-fermented manure averaged 1 : 1-5—2-7 in three successive years.
A. G. Po l l a r d.
Cold- and hot-fermented dung. Ge r l a c h (Z.
Pflanz. D üng, 1929, 8B, 529—545).—In field trials with hot- and cold-fermented dung recorded by Löhnis and his co-workers, the superiority of the former pro
duct is not always convincingly shown. Hot-fermented manure is not necessarily the practically' sterile mass suggested, but contains many organisms and enzymes which continue to decompose organic m atter and pro
duce carbon dioxide and ammonia. After the pre
liminary heating of the loose-layered stack to 60°
(Krantz) cooling may be fairly rapid, and unless com
pression of the stack occurs before the temperature falls, subsequent losses of carbon and nitrogen are not avoided. Initial loose-stacking to promote heating in the stack is unnecessary, and does not always bring about
the effects claimed. Farmyard manure is most economi
cally produced by immediate compacting of fresh stall manure and preventing leaching by rain. Building of stacks on loose stone drainage bottoms and the banking up of the sides with soil as the stack grows is
suggested. A. G . Po l l a r d.
H ow m ay nitrogen losses in the m aking of farm yard m anure be avoided ? H. v o n R a t h l e f (Forts.
Landw , 1928, 3 ; Bied. Z entr, 1929, 58, 491—492).—
Nitrogen losses from manure stacks are greatest in warm, dry, windy weather. Similar losses occur when the manure is spread but ploughing-in is delayed. As much as 50% loss of efficiency occurred in field trials when four days elapsed between spreading and ploughing.
A . G . Po l l a r d.
N itrification of farmyard m anure in soil. C.
Ba r t h e l (Z. Pflanz. Düng, 1929, 8B, 557—561).—The biological effects of the addition of farmyard manure to soil are due not to the addition of large numbers of micro-organisms, but to the stimulation of organisms already in the soil following added nutrients. The urinary nitrogen is the principal material concerned.
Other nitrogen in the dung is practically unnitrified after 12 months. The mechanism of the transformation of urinary nitrogen into nitrate is discussed. I t is suggested th a t the increased efficiency of hot-fermented manure (Krantz) may be due to the partial decompo
sition of the more stable nitrogen compounds in the heating stack leading to their more easy nitrification in
the soil. A. G . Po l l a r d.
N itrogen m anuring of low -m oor so ils. L.
Ri n n e (Z . Pflanz. D üng, 1929, 8B, 545—556).—In manuriai trials for hay on low-moor soils, nitrogen fertilises when used in addition to potash and phosphates were practically non-effective in dry seasons, particularly with a low rainfall in June. Comparative yields are recorded on horizons exhibiting various stages of peat decomposition. Generally speaking, nitrogen fertilisers were only profitable in seasons when the market price of hay was high. A. G . Po l l a r d.
Rational manuring of hops w ith special reference to phospates. L. R . Gr o b (Superphosphat, 1929, 5, 124 ; Bied. Z entr, 1929, 58, 490—491).—Farmyard manure forms the basis of hop manuring, but unless used with complementary artificial fertilisers leaf production may be excessive and cone formation limited. Phos- phatic fertilisers are most important as correctives in this respect, and tend also to improve the quality of the
hops. A. G . Po l l a r d.
Influence of lim e in phosphoric acid m obilisation of soil. 0 . K . Ke d r o v-Zik h m a n (Trans. Sci. Inst.
Fertilisers, Moscow, 1929, No. 61, 107—108).—Lime releases soluble phosphates by forming organic phos
phorus compounds which are readily attacked by micro
organisms. The calcium also replaces iron and alum
inium in phosphates. Calcium oxide is more effective than the carbonate. Ch e m ic a l Ab s t r a c t s.
Influence of lim e and raw phosphates on podsol- ised soil and crop yields. D . V. Dr u z h in in (Trans.
Sci. Inst. Fertilisers, Moscow, 1927, No. 45, 5—51).—
Liming of podsolised soils decreases their acidity and increases the nitrate content ; the water-soluble
B r itis h C h em ica l A b s tr a c ts —B .
74 Ce- XVI.—ä g e t c c l x c r e
-phosphorus decreases, whilst the plant--phosphorus increases. Raw phosphate does no t change the active acidity,, b u t affects nitrate formation and increases the yields. The active acidity of podsolised soils is that reaction of w ater cultures a t which the phosphoric oxide from raw phosphate becomes available to plants.
Ch e m i c a l Ar
STBACTS-Influence o f lim ing on the com position of oats.
P . T. Pk h it t jr ix (Trans. Sci. Inst. Fertilisers. Moscow.
1927, No. 45, 55—63).—Lime (up to 0*5%) increased the nitrogen content from 170-9 to 44$-1 m g , the phosphoric oxide content from 125-6 to 245 m g , the calcium oxide content from 69-2 to 161-0 m g , and the dry m atter from 17-57 to 27-22 mg.
Ch e m ic a l Ab s t r a c t s.
Lim ing experim ents [on so ils]. 0 . No l t e and M. K a c te rb e x g (Mitt. deut. Landw.-Ges, 1929, 565 : Bied. Z en tr, 1929, 58, 486— 487).—The importance of liming in conjunction with the increasing css of artificial fertilisers is emphasised. Field trials show th at the effect of lime on crop yields can be closely correlated with the sod's content of exchange acidity and calcium carbonate, b a t not with the total calcium content and hydrogen-ion concentration. A. G. P o lla rd .
Am m onia in fertilisers and its relation to the life of plants. D. N. Pr i a x i s h x i k o v Trans. Sci.
Inst. Fertilisers. Moscow, 1929. No. 61, 99—103).—
Ammonia is taken up by the plant more rapidly, and is assimilated more easily, than are nitrates, although excessive amounts of ammonia are the more injurious.
Nitrification is not desirable from the point of view of plant nutrition : nitrification regulates the concentration of ammonia. Ch e m ic a l Ab s t r a c t s.
Field and vegetation experiments with nitro
genous fertilisers in 1927. A. N. Lerediaxtzev (Trans. Sci. Inst. Fertilisers, Moscow, 1S29, No. 61, 35—60).—Experiments on the podsol and the northern and southern chernozem soils are described. Poppy, cotton, and rice specially needed phosphorus, whilst sugar beet and tomatoes specially needed potassium.
Physiologically acid nitrogen fertilisers (meludmg'urea) on acid soils with potassium. and phosphorus fertilisers which also leave acid residues decreased the yields.
On neutral and alkaline soils the physiologically alkaline fertilisers proved more satisfactory.
Ch e m ic a l Ab s t r a c t s.
Effect of different nitrogenous fertilisers as influenced b y soil reaction. Z te ls to r f f and B crow (Landw. Versnchs-Stat, 1929, 109, 237—252).—Ferti
lisers supplying 40 kg. N, 30 kg. P 20 j, and 80 kg. K20 per hectare were applied to oats and barley, the nitrogen being given as ammonium sulphate, sodium nitrate, cyanamide, and urea. In the case of oats neither the physiological nature of the nitrogenous fertiliser nor the soil reaction had any influence on the utilisation of the different nitrogen compounds, bu t with barley on an acid soil ammoniacal nitrogen was utilised to a smaller extent than nitrate-nitrogen. This difference disappeared as neutrality was approached. Liming produced a large increase in the yield of barley on soils with a high exchange acidity, but had no effect on the yield of oats. On soils with a high hydrolytic aciditv
liming produced no increase in the yield of barley . Hydrolytic acidity appears, therefore, to have very little influence on the growth of acid-sensitive plants.
E. Ho l m e s.
Seven-year investigation o f perm anent g ra ss
land flooded by water carrying potash effluents.
H . Im m e x b o r f y and C. A. We b e r (Landw. Yersnchs- S ta t, 1929,109,127—224).—The herbage of permanent meadows and pastures in 12 different areas regolarly or frequently flooded by rivers carrying effluents from potash works were examined to determine whether changes occurred in the botanical character of the flora, or in the yield and chemical composition of the hay.
The results indicate no harmful effects. Allegations th at observed periodic changes in the flora of permanent meadows and pastures were due to the effect <5 chlorides are unsupported. Chlorides are not responsible for isolated appearances of “ salt plants ” such as T rigbxkin mrtnt.imum, Scirpui Tabernaemmlani, Juncus Gerardi, Trifolium fragiferum, and Planlago maritime, which are m et with under wet conditions. Chemical ex a m in a tio n of the herbage and of the soil showed that neither was affected by the chlorine content of the flood water, the same being true of the yield and composition of the
hay. E. Ho l m e s.
E xperim ents with Solikam sk potassium salts in 1927. D . V. Dr c z h i x i x (Trans. Sci. Inst. Fertilisers, Moscow, 1929, No. 61, 71—88).—The salt (a mixture of potassium and sodium chlorides) compared favourably w ith other forms of potassium salts. Experiments on sugar beet, barley, lupins, potatoes, and fiax were performed. Ch e m ic a l Ab s t r a c t s.
P h ysiologically a d d nature of potash fertilisers.
0 . Lo e w (Chem.-Ztg, 1929, 53, S09).—Since ripe plants contain potassium as maiate, citrate, or combined with complex organic phosphoric acids even when potassium chloride or sulphate is supplied to the soil as fertiliser, the process of absorption of the potash by th e plant must involve an interchange of acid radicals in which the mineral acid is set free a t some s ta g e ; hence all commercial potash fertilisers must be considered physio
logically as acid salts. A. R . Po w e i x.
‘•N itrophoska ” a s a fertiliser. 0 . No l t e and M. Ra c t e r b e n g (Mitt. deut. Landw.-Ges, 1929,44, 62 ; Bied. Z en tr, 1929, 58, 485—4S9).—Fertiliser trials in 1928 confirm the satisfactory nature of “ Nitrophoska ” as a complete fertiliser. Soils must be well limed to ensure regnlar and certain results from this fertiliser.
A. G. Po l l a r d.
Action of the com plete m anure “ N itrophoska ”
Action of the com plete m anure “ N itrophoska ”