AGRICULTURAL. CHEMISTRY AGROTECHNY. 107 



dissolved in boiling acetone. The hot acetone solution is filtered, from which 

 on cooling the hydrocarbons separate out. The hydrocarbons are purified, 

 when necessary, by boiling with potassium hydrate in alcohol and recrystalliz- 

 Ing from acetone. An alternative process is also described. 



A number of hydrocarbons present in the flowers of Arnica montana, Matri- 

 caria cJmmomilla, Antennaria dioica, Artemisia mariiima, Tussilago farfara, 

 and Tilia europca are characterized and a formula assigned to them. 



[Action of hydracids and hydrolyzing agents on starch], W. O. De 

 CoNiNCK (Acad. Roy. Belg., Bui. CI. Sci., 1910, Nos. 6, pp. 515-517; 7, pp. 586, 

 5S7; abs. in Jour. Chem, Soc. [London], 98 {1910), No. 576^ I, p. 655). — It was 

 found that a mixture containing 3 gm. of starch, from 35 to 40 gm, of water, 

 and 2 cc. of concentrated hydrochloric acid, when held at 14° C. will reduce 

 Fehling's solution only slightly after 3 days and markedly after 6 days. The 

 hydrolysis is more active at 100°. Concentrated hydriodic or hydrobromic 

 acids act similarly at ordinary temperatures, while a dilute solution of the 

 former will hydrolyze at a higher temperature. 



" The following substances dissolved, or suspended, in water also hydrolyze 

 starch : Ferric, platinic, auric, and stannous chlorids ; chlorin ; potassium f er- 

 rocyanid, ferricyanid, dichromate, and hydroxid ; sodium hydroxid, hydrogen 

 carbonate, and dichromate ; ammonium, lithium, barium, strontium, and calcium 

 hydroxids; cupric sulphate; cobalt nitrate; nitric (dilute), chromic (dilute), 

 acetic, tartaric, benzoic, picric, and other organic acids." 



Stachydrin and other bases present in stachys tubers and in citrus leaves, 

 E. SCHTJLZE and G. Tkier {Ztschr. Physiol. Chem., 67 (1910), No. 1, pp. 59- 

 96; abs. in Jour. Chem. Soc. [London], 98 (1910), No. 57 Jf, II, pp. 7^3, 7U)-— 

 After detailing the method for isolating stachydrin from the tubers of Stachys 

 ttiberifera and the foliage of Citrus aurantium, the authors point out that from 

 the former a yield of 0.18 per cent of base, calculated from the dry substance, 

 and small amounts of arginin, cholin, trigonellin, alloxuric bases, glutamin, 

 and tyrosin were obtained. Citrus leaves yield about the same amount of 

 base, and cholin and alloxuric bases are also present. The chemical and 

 physical properties of stachydrin as obtained from the above sources are given. 



The reactions of saponin, O. Reichard (Pharm. Zentralhalle, 51 (1910), 

 No. 52, pp. 1199-1204; abs. in Chem. Abs., 5 (1911), No. 5, p. 969).— This is a 

 description of various reagents and reactions for this substance. 



A method for the study of proteolytic ferments, P. A. Kobeb (Jour. Biol. 

 Chem., 10 (1911), No. 1, pp. 9-14). — This preliminary paper contains results 

 of experiments on which the author hopes to base a method for following the 

 action of ferments upon peptones and synthetic polypeptids. Essentially it 

 consists in making copper salts of the neutral digestive mixtures, bringing them 

 to the boiling point, and adding a small amount of alkali. Where amino acids 

 are present an immediate precipitate of copper hydrate will be produced, which 

 is directly proportional to the amount of amino acids present. The author 

 thus far has tried 6 amino acids, which were found to adapt themselves to the 

 technic admirably. 



Question as to the identity of pepsin and chymosin, W. Sawitsch (Ztschr. 

 Physiol. Chem., 68 (1910), No. 1, pp. 12-25; abs. in Jour. Chem. Soc. [London], 

 98 (1910), No. 576, II, p. 876).— The author points out that with Hammarsten's 

 method for isolating pepsin the chymosin is not destroyed but its activity is so 

 altered that it shows a negative coagulating property. The rennin from calves 

 when kept in a thermostat becomes so changed that it resembles Bang's para- 

 chymosin. Ferment solutions obtained from various animals had different prop- 

 erties, but from this it does not follow that the pepsins from all animals are 

 not alike, as the only difference lies in the amount of resistance or reactivity. 

 22214°— No. 2—12 2 



