AGRICULTURAL CHEMISTRY AGROTECHNY. 109 



" In the assay of paiicreatin for starch hj-drolysis, as well as all the diastasic 

 ferments, the kind of starch used is of prime importance and in stating the 

 strength of each it should be in terms of the particular starch employed." 



In tests with papain it was found to make very little difference what kind of 

 raw beef was used when the ferment was acting in acid media, but if the nature 

 of the beef was changed (for instance, by cooking) papain was found to lose 

 its solvent action. Rennet was found to be influenced in its coagulating power 

 by the chemical composition of the milk as regards the presence and amount of 

 inorganic salts, particularly calcium salts. The mixing of the rennet with the 

 milk, the temperature at which the milk was kept before and during the test, 

 and finally the breed of cows from which the milk was obtained were additional 

 factors. 



Action of the salts of the gold group upon the saccharification of starch 

 by amylolytic ferments, C. Gekbeb (Conipt. Rend. Soc. Biol. [Paris]. 70 

 (1911), No. 13, pp. 5^7-553). — This is a continuation of the studies previously 

 noted (E. S. R., 25, p. 107) with the salts of this group as to the hydrolysis of 

 starch. Zinc chlorid acidulated with hydrochloric acid, potassium oxalate 

 acidulated with oxalic acid, copper chlorid, and the various chlorids of gold 

 and platinum were employed. Some tests upon the coagulation of milk with 

 these chemicals are also included. 



Action of the salts of the alkali metals upon the saccharification of starch 

 by amylolytic ferments, C. Geebeb (Compt. Rend. Soc. Biol. [Paris], 70 

 {1911), No. 10, pp. 391-^97).— The author reports his results with the salts 

 from inorganic, monobasic acids (chlorids, nitrates, and fluorids of sodium, 

 potassium, and ammonium), the salts of dibasic acids (sodium sulphate and 

 bisulphate), and those from tribasic acids (tri-, di-, and monopotassium ortho- 

 phosiihates). Experiments were also made with the organic salts of monobasic 

 organic acids from the aliphatic and aromatic series (sodium formate, acetate, 

 butyrate, propionate, valeriate, stearate, palmitate, benzoate, and salicylate), 

 and salts of the polybasic acids (potassium and sodium oxalate and citrate). 



Action of some salts upon the saccharification of Fembach and Wolff's 

 soluble starch by amylolytic ferments, C. Geebee (Compt. Rend. Soc. Biol. 

 [Paris], 71 (1911), No. 27, pp. 247-2-}9)-— This work was done with the 

 chlorids of cadmium, bichlorid of mercury, zinc chlorid, cupric chlorid, silver 

 nitrate, potassium oxalate, sodium citrate, and quinin hydrochlorate. 



In regard to catalase, Grimmer (MUchto. ZentbL, 7 (1911), No. 7, pp. SH- 

 316). — A discussion in regard to the findings of W. D. Kooper (E. S. R., 26, 

 p. 112) with the various forms of apparatus for determining the catalytic 

 activity of milk. 



The examination of substances important in agriculture and the indus- 

 tries, J. KoNiG (Die Untcj-suchung landivirtschaftlich und gewerhUcJi voiehtiger 

 Sioffe. Berlin, 1911, 4. ed. rev., pp. XX+1226, figs. 426).— This is the fourth 

 edition of this work ( E. S. R., 17, p. 1133). 



A quantitative method for determining small amounts of potassium, E. A. 

 IMitscherlich, K. Celichowski, and H. Fischer (Landw. Vers. Stat., 76 

 (1912), No. 1-2, pp. 139-155). — The method which follows is recommended for 

 determining small amounts of potassium in soil extracts which are obtained 

 by extracting soil with water, saturated with carbon dioxid, and any other 

 material containing potassium. 



To 250 cc. of the soil solution in a beaker, 5 cc. of concentrated nitric acid 

 and 5 drops of dilute (1:3) sulphuric acid are added, and the whole concen- 

 trated to a bulk of 20 cc. The concentrated solution is transferred quantita- 

 tively to a platinum or quartz dish, evaporated to dryness, and the organic 

 matter destroyed by heating the dish for a short time. 



