AGRICULTURAL CHEMISTRY AGROTECHNY. 305 



coiupouncl of one of the dijiestioii products of casein (polypetid phosphoric 

 acids), separated by Reh's method (E. S. R., 19, p. 1108), was studied by the 

 author and is described as a yellow-brown powder easily soluble in cold water 

 but in-soluble in alcohol, ether, and acetone. 



Phosphoric acid was split off when this body was treate<l l)y either concen- 

 trated acids or dilute alkalis. By boiling the aqueous solution (1:300 or 

 1 : 400) a microscopic crystalline precipitate of the calcium salt was obtained. 

 In higher concentrations this product was gelatinous, which indicated that a 

 mixture of various salts was present. Much of the calcium salt was deposited 

 on boiling a concentrated solution of the crude salt. 



Phosphorus determinations were made in the ])recipitate and solution, 

 respectively. After dissolving the precipitate in water and acetic acid, neu- 

 tralizing, and fractionating with zinc acetate, lead acetate, and copper acetate 

 three peptone-like bodies containing phosiihorus were obtained, which differed 

 from each other in the readiness with which they yielded inorganic phosphorus. 

 In the original solution an acid was present which could be precipitated with 

 uranyl acetate. 



Physico-chemical investigations with lecithin and cholesterin, O. Porges 

 and E. Neubauer iZtschr. Chcm. n. Indus. KoUoidc, .3 (1!)09), yo. Jf, pp. 

 193-197; (lbs. in Zcnthl. PhimoL, 23 {1909). Xo. 2',, p. 8,S'0).— The electrolytes 



(in concentrations of from to ) of the alkali salts of lecithin 



(alcoholic lecithin solutions) show no changes, but the alkali earth salts are 

 precipitated within 24 hours. Zinc chlorid and cadmium chlorid compounds 



(up to TKF.) ^i'6 precipitated at once. Mercuric chlorid precipitates only 



partly in the higher concentrations, while cadmium chlorid and manganese 

 chlorid are only active in medium concentrations. Tartaric acid, on the other 

 hand, has a wider range of activity. Among the nouelectrolytes. dextrose and 

 mastic solutions i)roduced no changes, while colloidal ferric hydrate and ferric 

 chlorid jirecipitate in middle concentrations. The reactions are therefore 

 characteristic of colloidal reactions. 



About carnaubon, E. K. Dunham and C. A. Jacobson (Zfsclir. Physiol. 

 Chcvt., G'f (1910), A'o. 3-.i, pp. 302-315). — A glycerin-free phosphatid is described 

 which simulates lecithin and has galactose as its nucleus. 



Fat analysis and fat chemistry for the year 1909, W. Fahrion (Ztschr. 

 Angcw. Chiin., 23 {1910), Ao.s. 19. pp. Ji'i6-'i50 ; 11, pp. 1,90-498) .—A retrospect 

 is given of the chief advances made in the chemistry of fats during 1909. 



The examination of the volatile acids in edible fats, E. Poppe {Abs. in 

 Clicni. Ztij; 3Jf {1910), No. 26, p. 222). — The author investigated the various 

 methods which have been introduced during the last 10 years, and concludes that 

 the Reichert-Meissl and Wauters methods are the most reliable. 



An extraction apparatus, N. Roberts {Amer. Chem. Jour., J,3 {1910), No. 5, 

 pp. J,18-.'i25, figs. 2). — An apparatus is described which can be employed for 

 large charges, as much as .3 kg. of substance. 



The simple carbohydrates and the g'lucosids, E. F. Armstrong {London and 

 New York, 19 JO, pp. IX + 112). — The aim of this monograph is to present the 

 more important facts which relate to the chemistry of the simi)le carbohydrates 

 and glucosids, and particularly matter not available in the ordinary text-books. 



As to the identity of pepsin and chymosin, W. Van Dam {Ztschr. Physiol. 

 Chcm., (J.'f {1910), No. 3-.'i, pp. 316-336) .—ruve pig enzym when digested with 

 0.2 per cent hydrochloric solution produces a solution which loses its capacity 

 for coagulation, but is still capable of digesting large amounts of egg albumen 

 at concentrations of 0.72X10-''-n-PI, On purifying a heated solution by dialy- 



