RECliNT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



The relation of investigations on colloids to agricultural chemistry, II, 

 P. Ehrenbkrg iZtschr. Chem. v. Indtif<. KoUoidc, // (1909). No. 2-3, pp. 7H-S(i ; 

 o&.s. //). yjxchr. Aiif/rir. Clirm.. 22 (1909), No. 28, p. i7//5).— This is a further 

 contribution to the discussion already noted (E. S. R., 21, p. 301). 



Colloid substances in cultivated soil, I*. Koiiland (Ztschr. Chem. ii. Jiulits. 

 KoUokJc. 5 {1909), No. 5, pp. 2Ji3, 2Ji.'i'\. — Replying briefly ta statements by 

 Ehrenborg (see above) the author restates certain points which have been 

 brought out in his own investigations (E. S. R., 21, p. 117). He believes It safe 

 to conclude that the more colloid substances soils contain the more productive 

 they are. 



Notes on colloid chemistry as applied to soil investigation, P. EiiRENUKKd 

 (Ztschr. Chem. u. Imliis. KoUoide, 5 (1909), No. 2, pp. 100, iO/).— Brief his- 

 torical notes on investigations relating to this subject are given. 



Colloidal-chemical processes in wood formation, H. Wislicenus (Tlianiiid. 

 Forstl. Jahrb., 60 (1909), pp. 313-358, figs. 4; a&s. in Chem. Ztg., 33 (1909). 

 No. 102, Repert., p. .'/'/.?). — The author comes to the conclusion that the vital 

 process of wood formation is regulated by and dependent upon certain laws of 

 colloidal chemistry. 



The question of the nomenclature of chlorophyll chemistry, L. March- 

 LEWSKi {Chem. Ztg., 33 (1909), No. 98, p. 871; abs. in Chem. ZentU., 1909, II, 

 No. 13, pp. 1056, 1057). — A discussion relating to the terms phaophytin v. chloro- 

 lihyllan and phyllogen. The author also deems it advisable to retain the term 

 alkachlorophyll for the alkali-changed products instead of substituting for it 

 Willstatter's chloro|)hyllin. 



Protein hydrolysis by hydrofluoric acid, Ii. Hugoitnenq and A. Morel 

 (Com lit. h'riii]. Acad. .S'cj. [Paris], l.',9 (1909). No. 1, pp. -^i-/,.?).— Gelatin was 

 completely hydrolyzed by a 15 per cent solution of hydrofluoric acid, whereas a 

 20 to 30 per cent solution of this acid yielded only amino acids with dipeptids 

 and tripeptids. A 35 per cent acid solution gave polypeptids of a more complex 

 structure, and a cctutinued hydrolysis of one of these gave 5 acid amids, viz, 

 arginin, lysin, alananin, phenylalanin, and glycocoll. A 45 per cent solution 

 of the acid gave only dianiins. These peptids were not synthetic products. 



The action of dilute acid on edestin, G. G. Petrow (Izv. Moslcov. Selsk. 

 Khoz. Inst. [Ann. Inst. Agron. Moscou], 15 (1909), No. 2, pp. 200-218).— The 

 author reports the results of an experimental study of the action, at different 

 temperatures, of 4 per cent sulphuric acid on crystalline edestin. 



According to his summary, the acid has a very marked effect, inducing cleav- 

 age to amido acids, organic bases, and ammonia. Peptones to the extent of 50 

 per cent" of the nitrogen present are formed at first, but later the quantity dimin- 

 ishes. The peptones are evidently an intermediary step in the hydrolytic cleav- 

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