X V — LEATHER; GLUE

P reservation of h ides w ith brine and sa lt. (Miss) M. Kaye (J.S .C .I, 1929, 48, 141— 148 t).—The pro­

duction of a perfectly preserved skin or hide necessitates a raw m aterial in good condition, an efficient preserva­

tive, properly applied, and the prevention of subsequent conditions which would adversely affect the product.

The efficiency of sodium chloride alone, either as brine or as crystals, as a preserving agent, and the effect of

the addition of certain “ d é n a tu ra n ts” are discussed.

Microscopical observations on the histological changes which occur when hides are treated w ith salt solutions of different concentrations, and a t different periods of tim e after death, show th a t it is essential to use either solid salt or a brine of a t least 23% concentration, and th a t salting m ust be commenced w ithin a few hours after death or perm anent damage to the skin tissues will result. If the tem perature be above 22°, the con­

centration of the brine should n o t fall below 27%.

Brining previous to salting appears to be advantageous in th a t i t ensures rapid penetration and prevents undue shrinkage. Of the colourless dénaturants examined, sodium bifluoride and sodium carbonate improve the preserving action of the brine on the sldn tissues ; sodium fluoride gives approxim ately the same result as the saturated brine alone ; sodium bisulphate produces some shrinkage of the tissues, and magnesium chloride appears to loosen the hide fibres too much. Of the coloured dénaturants which are said to produce stains, potassium dichromate does not produce stains on hides, whereas copper sulphate produces stains which are only tem porary if the hides are fresh, b u t become perm anent if the hides are salted in a stale condition, or become dried after salting. Some common defects of salted hides (marbled grain, “ pipe,” loose grain, greasiness, and veininess) are attributed to different degrees of autolytic and bac­

terial action. Marbled grain appears to be the result of surface bacterial attack, whereas veininess in many cases is the result, of partial destruction of the walls of blood-vessels.

Sulphuric acid in vegetable-tanned leath er.

R. F. In n es (J.S .C .I, 1929, 48, 149—152 t) .—Partly- tanned hides which have been plumped by immersion in dilute sulphuric acid lose the whole of the acid absorbed as soon as they are “ struck through ” by subsequent suspender liquors. The use of sulphuric acid in th e early stages of tanning should not be harmful to th e finished leather and cannot be the cause of a positive sulphuric acid test by the Proctor-Searle method.

When sulphuric acid is found in finished leather it m ust have been applied to the tanned leather in the later stages of manufacture. Sulphuric acid combined with pelt (collagen sulphate) is markedly resistant to the action of both tim e and tem perature. The rotting of leather is often associated w ith a high content of sul­

phuric acid, b u t a high content of sulphuric acid does not always lead to ready rotting, and attention is now being directed to the effect on rotting of the nature of the tannin used.

D eterm in ation of th e p n value of tan liquors and lim e liq u o rs. (Miss) W. B. P le a s s (J.S .C .I, 1929,48, 152— 156 t) .—The glass electrode, hydrogen electrode, quinhydrone electrode, and colorimetric methods of determ ination of p n values are discussed. Accurate and trustw orthy results have been obtained by the glass electrode m ethod for all kinds of liquors. The hydrogen electrode m ethod gives accurate and tru s t­

w orthy determ inations when th e liquors are free from substances which produce an oxidation-reduction potential. The quinhydrone electrode is u n tru st­

worthy for all trade ta n liquors. When a capillatoj

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

7 3 0 C l. X V I.— Ag r ic u l t u r e.

compensating cell is used to compensate for the colour of the liquors, the capillator m ethod gives results which are accurate to 0-2 ]>u u nit for all types of tan liquors, b u t is not applicable to lime liquors.

Effect of p retreatm en t on h y d r o ly sis of hide pow der b y satu rated ca lciu m h yd roxid e so lu tio n s.

A. W. Thom as and M. W. Ke l l y (Ind. Eng. Chem , 1929, 21, 701—702).—Samples of hide powder were exposed in atm ospheres of 0, 50%, and 100% hum idity respectively a t 4°, room tem perature, and 37-5°, until the protein had reached equilibrium with the moisture in the atmosphere, and th e ra te of hydrolysis by lime w ater was determ ined on them . I t is shown th a t previous thorough desiccation of hide powder causes m arkedly greater hydrolysis in saturation solutions of calcium hydroxide. In similar tests the powder after pretreatm ent with sodium sulphate decomposed more readily in the calcium hydroxide th an after p re treat­

m ent w ith sodium chloride. D. Wo o d r o ff e. In flu en ce of acid s on th e fixation of w a ttle tannin b y h ide pow der. A. W. Tho m as and M. W.

Ke l l y (Ind. Eng. Chem , 1929, 21, 697—698).—P or­

tions of hide powder were treated w ith solutions of w attle bark tannin brought to different values by means of various acids for 6 or 2 4 h rs , filtered in W ilson- K ern extractors, and the fixed tannin was determined.

I t is shown th a t the order of diminishing influence of th e acid used for p n 2-5—3-0 was acetic, lactic, formic, tartaric, oxalic, hydrochloric for a 6-hr. period of treatm ent, and acetic, lactic, succinic, formic, citric, tartaric, oxalic, chloroacetic, hydrochloric for a 24-hr.

period. The la tte r list is alm ost inversely proportional to the dissociation constants of the acids.

D. Wo o d r o ff e. Pa t e n t s.

T reatm en t o f leath er. M. Se g o r ia (U .S .P . 1,696,867, 25.12.28. A p p l, 30.11.27).—L e a th e r is re n d e re d s m o o th e r a n d m o re d u ra b le a n d p lia b le b y t r e a tm e n t w ith a m ix tu r e of 25 p ts . of w h ite p in e oil, 5 - 8 — 6 -0 p ts . of lin se e d oil, a n d 6 p ts . of b eesw ax .

R . Br ig h t m a n. A rtificial leath er (B.P. 314,571).—Sec X III. H ard­

ened gelatin la y ers (B.P. 288,146).—See X X I.

XVI.— AGRICULTURE.

U ltim ate natural structure of so ils . G. J . Bouyoucos (Soil S ci, 1929, 28, 27—37).—The ultim ate natural structure of soil granules m ay be examined by allowing a dried natural soil to slake and disintegrate in a large quantity of w ater w ith gentle agitation.

The gradation in the size of granules so obtained is stable, and considerable external force m ust be applied to reduce the original sizes of the granules. Mechanical analyses of such slaked soils m ay be made by the hydrometer method. The ultim ate natural structure of soils, rather th an the distribution of the ultim ate particles, should form the basis of investigation of many of the physical properties of soils. The"ordinary structure of field soils is not the ultim ate natural structure, b u t a tem porary structure resulting from the immediate treatm ent received. A. G. Po l l a r d.

S o il profile stu d ies. I. S o il as an independent b od y and so il m o rp h o lo g y . J . S. Jo f f e (Soil Sci, 1929, 28, 39—54).—The form ation of soil is discussed with special reference to the recent work of Russian investigators. The introduction of a special section of soil science for the study of buried soils is suggested.

A. G. Po l l a r d. E xchange reactions of in so lu b le alkaline-earth ph osp h ates in p erm u tits and c la y s. E. Un g e r e r

(Kolloid-Z, 1929, 48, 237—241).—Experim ents have been carried out on the interaction of potassium and ammonium perm utits and of clay w ith magnesium phosphate, magnesium ammonium phosphate, and calcium phosphate. Exchange of bases takes place.

The reactions are of im portance in the decomposition of difficultly-soluble phosphates in soils.

E. S. He d g e s. C hem ical c om p osition of F lorid a E verglades peat so ils , w ith sp ecia l referen ce to th eir inorganic co n stitu en ts. H. E. Ham m ar (Soil S ci, 1929, 28, 1— 13).—Analyses of a num ber of soils are recorded and the formation of these soils is discussed.

A. G. Po l la r d. Character, prop erties, and p o ssib le uses of bentonite, a so d iu m cla y . R. M. Woodman and E. MoK. Taylor (J.S .C .I, 1929, 4 8 , 121— 125 t).—

Bentonite, a colloidal clay, has been proved to consist mainly of a sodium clay, exhibiting the usual character­

istics of a sodium clay such as liberation of sodium hydroxide by hydrolysis in water, impermeability to water, etc. When suspended in w ater the sample examined yielded a solution of p n 10-5. A determination of the replaceable bases showed 69-9 mg.-equiv. of replaceable sodium and 23-9 mg.-equiv. of replaceable calcium per 100 g. of dry m aterial. I t has been proved a good emulsifier for certain oils, usually forming the oil-in-water type of emulsion suitable for the spraying of plants. Evidence is given showing the formation of dual types with cresylic acid. In addition, bentonite has been proved to be a water-softener acting by base exchange, th u s being useful in cases of perm anent hard­

ness. The fault of bentonite as a practicable emulsifier and water-softener is its impermeability to water.

B a se exch an ge in orth oclase. J . F. B r e a z e a l e

and O. C. Ma g ista d (Ariz. Agric. Exp. Sta. Tech.

B u ll, 1928, No. 24, 609—629).—The solubility in w ater of the potassium in orthoclase varies with the origin of the sample, the fineness of subdivision, and the ratio of solid to liquid. T reatm ent w ith alkaline salt solutions increased, whilst treatm en t w ith acid solutions decreased, th e base-exchange capacity of finely-ground orthoclase. Digestion of ignited orthoclase w ith alkaline solutions m ay increase the base-exchanging capacity beyond th a t of non-ignited m aterial. When solid orthoclase occurs in the soil in presence of calcium, magnesium, or sodium zeolite, an equilibrium between the potassium in solution and the zeolites will be estab­

lished. The plant probably feeds largely on hydrolysed zeolitic potassium. The zeolites of calcium, magnesium, and sodium may act as stabilisers by fixing much of the soluble potassium during periods of little p lan t growth, and slowly liberating it as required by plants.

Ch e m ic a l Ab s t r a c t s.

B r itis 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. 731

H y d ro ly sis of so d iu m and p o ta ssiu m zeo lites w ith p a rticu lar referen ce to p o ta ssiu m in the so il so lu tio n . 0 . C. Ma g is t a d (Ariz. Agric. Exp. Sta.

Tech. B u ll, 1928, No. 22, 521—547).—The am ount of alumina present as sodium alum inate on hydrolysis of sodium zeolite is a logarithmic function of the j >h of the solution. A t equal dilutions th e hydrolysis of potassium zeolite is less th an th a t of sodium zeolite ; in m ixtures the hydrolysis is m utually depressed. The depression of the hydrolysis of potassium zeolite by calcium zeolite is diminished in solutions containing carbon dioxide. If the am ount of replaceable potassium in 100 g. of soil is known, th a t in the soil solution a t any dilution can be calculated. The am ount and rate of hydrolysis of replaceable potassium are discussed in relation to p lan t feeding. Ch e m ic a l Ab st r a c t s.

Soil zeo lites and plan t grow th . J . E. Bk e a z e a l e

(Ariz. Agric. Exp. Sta. Tech. B u ll, 1928, No. 21, 499—520).—The concentration of potassium in soil solutions is always low, and cannot exceed the sum of the solubilities of th e potassium in the zeolite and in the orthoclase. Hence a heavy application of potassium salt does n o t proportionately increase the soil-extract potassium ; hence, also, potassium is n o t readily leached away. The presence of other salts with replaceable bases, particularly nitrates, stim ulates the absorption of potassium from solutions containing potassium zeolites. The zeolite residue of alumina and silica, after absorption of potassium by plants, exists either in the colloidal state or in some form of combina­

tion ; zeolite m ay be regenerated b y addition of a salt containing a replaceable base. Ignited and acid- treated soils which have lost their property of base- replacement are p artly restored by treatm en t with salt solutions having a neutral or alkaline réaction.

Ch k m ic a l Ab s t r a c t s. A vailab ility of p o ta ssiu m in so m e S cottish so ils.

R . St e w a r t (J. Agric. S c i, 1929, 1 9 , 524—532).—The total potash content of 34 samples from 13 soils typical of large areas in the E ast of Scotland averaged 2-04% . No relation was found between total potash and potash soluble in hot conc'entrated hydrochloric acid ; the average figure for the latter was 0-50% . In the profile samples there was generally an increase in solubility with increase in depth. The average am ount of citric-soluble potash was 0-0074%, and w ith one notable exception citric solubility decreased with depth.

The citric-soluble potash varied from 26 to 79% of the exchangeable potash. The Neubauer method of analysis applied to 10 of the samples indicated a deficiency of available potash in most cases, and comparison w ith the figures for exchangeable potash indicated th a t the content of exchangeable potash determines the am ount of potash which can be absorbed from a soil by the

seedlings. E. Ho l m e s.

R apid electrom etric d eterm in ation of chloride content o f s o ils . R. J . Be s t (J. Agric. S c i, 1 9 2 9 , 1 9 ,

533—540).—An apparatus consisting essentially of a quinhydrone electrode and an Ag|AgCl electrode connected internally by means of a 3% agar-saturated potassium n itrate salt bridge, in series with a galvano­

m eter of such a sensitivity th a t it gives a deflection of

one division per m icro-am p, has been devised. The AgiAgCl electrode and the agar tube are dipped into a suspension of 4 g. of soil in 50 c.c. of distilled water, and titration with silver nitrate follows the usual course.

Using a buffer solution of p u 3 -0—3-3, if titratio n is carried out between 25° and 16° with an 2V/35 • 46 silver nitrate solution the current reverses its direction at the end-point of the titration. E. H o lm e s .

Cobaltinitrite (volum etric) m ethod of d eter­

m in in g p otassiu m in so il extracts. G. Mil n e (J.

Agric. S c i, 1929,1 9 , 541—552).—A volumetric cobalti­

nitrite method, which is described in minute detail, enables known amounts of potassium to be determined, independently of the presence of alkaline-earth sul­

phates, or phosphates, provided the am ount of potassium is not varied over too great a range. The factor 0-000830 g. K 20 per c.c. of 0 -1 iV-permanganate suits the pre­

scribed procedure over a range of 3—50 mg. of K ,0 . The method is applicable to plant-ash analyses, to more accurate sm all-quantity work on soils than the per­

chlorate method, and also to citric acid extracts.

Analyses of ammonium chloride extracts have not proved

satisfactory. E. Ho l m e s.

A lterations of so il structure b y natural and artificial m an u res. G. H a g e r (Mitt. deut. landw.

G es, 1929, 1, 143 ; Bied. Z en tr, 1929, 5 8 , 293— 294).—

Humus and basic calcium compounds are indispensable for the maintenance of good soil structure. Calcium chloride and nitrate and gypsum are less effective since they are n o t intim ately associated w ith the soil particles and cannot remove soil acids. Basic magnesium compounds are similarly favourable to soil structure b u t to a smaller extent than the corresponding calcium salts. Owing to the formation of ammonium carbonate from the urea contained in liquid manure the latter tends to incrust and “ puddle ” heavy soils.

Superphosphate has no effect on soil structure, and no unfavourable effects result from the use of ammonium sulphate or combined fertilisers containing ammonium salts. The unbalanced use of potash salts and of sodium n itrate is injurious to soil structure, b u t the ill-effects m ay be avoided by the judicious combination with other fertilisers. A. G. P o l l a r d .

C om parative effect of various nitrogen fertilisers on bearing apple trees of lo w vigou r. A . L. S c h r a ­ d e r and E. C. A u c h t e r (Proc. Amer. Soc. Hort. S ci,

1927, 229— 234).—Sodium n itrate causes a greater term inal spur and tru n k circumfercnce growth and higher yields th an ammonium sulphate. The total and soluble nitrogen of spurs was greater for sodium nitrate ; spur starch in June was favoured by ammonium sulphate. C h e m ic a l A b s t r a c t s .

N itrogen ou s m anuring of grasslan d . H. W.

G a r d n e r , J . H. S m ith , J . W . R e id , and H. R . W i l l i a m s (J. Agric. S c i, 1929, 19, 500— 523).—The results of two years’ treatm ent of grass by periodic dressings w ith nitrogenous manures, following autum n complete dressings, coupled with systematic grazing, indicate th a t the addition of 4 cwt. of ammonium sulphate in fractional am ounts raised the stock-carrying capacity of the treated plots by about 50% in 1927 and 20% (with 3 cwt.) in

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

7 3 2 C l. X V I.—Aq e i c u l t d e e.

1928. The percentage of clovers on the nitrogen- treated plots was only one quarter th a t on the controls, whilst the dry m atter of the herbage averaged 17-7%

and 15-5% respectively of crude protein. The tips of the young grass contained 17-72% of dry m atter, of which 27-2% was crude protein, and the rest of the herbage 14-41% of dry m atter (19-5% protein).

E . Ho l m e s. Yield in cereals. VI. A . Influence of n itro­

genous top -d ressin g on w h eat. B . Influence of d isea se (“ take-all ” ) on the yield of w heat. L. E.

Do u gh ty, F. L. En c l e d o w, and T. K. Sansom (J.

Agric. S c i, 1929, 1 9 , 472—490).—An elaborate analysis of results of tillering counts, yield measurements, and other examinations of a series of 1-ft. row samples of nitrogenously manured winter wheat, grown on an imperfectly drained gault clay in the Eastern Counties, leads to the conclusions th a t increased survival of tillers is not induced by a February nitrogenous dressing.

Owing to the disease “ take-all ” yields were low, but the dressed strips yielded a t the rate of 26-4 bushels per acre and the untreated a t 19-1 bushels per acre. The common practice of February or March top-dressing augments ear size, b u t cannot raise yield per acre in, any other way. For increased ear-formation December application might be necessary, b u t practical considera­

tions suggest a half dressing a t sowing and the rest a t the beginning of February. E . Ho l m e s.

Effect of anions of p o ta ssiu m sa lts on potato heads and the effect of root a ctiv ity on the s o il.

W. VON Br e h m r r (Ernähr. Pflanze, 1928, 2 4 , 393—397 ;

Chem. Z e n tr, 1929, i, 691—692).— The p n of the soil, adjusted to 4-0 by addition of potassium hydrogen sulphate after fertilisation, was increased by plant growth to 7-3. In the “ chloride and sulphate series ” the pn curve was nearly parallel w ith the head-height.

A. A. Eldrtd ge. A n a ly sis o f tom ato p lan ts. I . 0 . O w f.n (J. Agric.

S ci, 1929, 1 9 , 413—432).—At the Cheshunt Research Station phosphorus does n o t appear to play such an im portant role in tom ato culture as American work suggests. Unmanured plants give fru it of inferior quality, b u t the weight ratio of fruit to foliage and stems is about 2 • 6, as compared w ith 1-6 on th e manured plants. The removal of plant food per plant- averages 9-3, 2-0, and 18-2 g. of N, P 20 5, and K 20 respectively on m anured plants, and only 4-9, 1-0, and 2-8 g.

respectively on the unm anured plants. Analyses of trimmings and leaves a t different periods of the year suggest th a t the actively growing parts are richest in plant nutrients. Freak fruits contain the following percentages of N, P 20 5, and K ,0 :0-16, 0-05, and 0-32 ; and 0-18, 0-035, and 0-055 in the manured and u n ­ manured plants respectively. Tom ato plants yielding good crops show a relatively high ash content. The th ird and fourth trusses on a p lan t are richest in plant nutrients* b u t the relative am ounts of potash in the aerial parts of the p lan t fall as the season progresses.

E. H o lm e s ; A ctive lim e of dephosphoration sla g s and of so-called d isaggregated phosp h ates. C. B r i o u x and E. Jo in s (Compt. re n d , 1929, 1 8 9 , 117—119).—

In addition to free lime, th e slags contain calcium silicates and silicophosphates which are more or less rapidly decomposed by w ater in the presence of carbon dioxide, with the form ation of calcium carbonate. Their activity m ay be measured from the gradual change in p n value when 1 g. is well mixed w ith 500 g. of an acid soil of known lime requirem ent and p n value, in the presence of 20% of water. In th e cases recorded and w ith a soil of p n 5-49, decomposition was com­

plete after 8 days, and the active lime content (including alkalinity due to soda and potash in the case of the disaggregated phosphate) exceeded 30%. W ith more alkaline soils, however, it is less. J . Gr a n t.

F u n gicid al p rop erties of certa in sp ra y -flu id s.

V. W. G o o d w in , H . M a r t i n , and E. S. S a lm o n (J.

Agric. S ci, 1929, 1 9 , 405—412 ; cf. B , 1926, 506).—

In experim ents with the fungus Sphcerolheca humuli (D C .), B u r r , on a hop known to be susceptible to mildew, it was shown th a t a solution of dicalcium hydrogen arsenate containing 0-0125% As20 5 was fungicidal, whilst th e solution containing 0-006% was not. In a similar m anner calcium thioarsenate solution

In experim ents with the fungus Sphcerolheca humuli (D C .), B u r r , on a hop known to be susceptible to mildew, it was shown th a t a solution of dicalcium hydrogen arsenate containing 0-0125% As20 5 was fungicidal, whilst th e solution containing 0-006% was not. In a similar m anner calcium thioarsenate solution