RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICTJLTTJSAL CHEMISTRY— AGROTECHNY. 



The casein and salts of goat's milk, A. W. Boswobth and L. L. Van Slyke 

 (New York Sta. Tech. Bui. 46 {1915), pp. 3-15; Jour. Biol. Chan., 24 {1916), 

 No. 3, pp. 113-189). — Continuing earlier work (E. S. K., 33, p. 6(30) an iuvesstiga- 

 tion was made of the chemical composition of goat's milk. 



The casein prepared from goat's milk forms a series of compounds with bases 

 which indicate that its valence, combining proportions, and molecular weight 

 are the same as that of the casein of cow's milk 



The soluble constituents of goat's milk are sugar, potassium, sodium, and 

 chlorin. The albumin, inorganic phosphates, calcium, magnesium, and citrates 

 are partly in suspension and partly in colloidal solution. The fat and casein 

 are entirely in colloidal solution. 



The real acidity of the milk, obtained after precipitating the calcium with 

 neutral potassium oxalate, is considerably less than that of cow's milk. Goat's 

 milk, in contrast to cow's and human milk, contains tricalcium phosphate. 

 The total amount of salts in human milk is about one-third that in cow's or 

 goat's milk. The number of different salts appears to be greater in goat's milk, 

 and the amount of chlorids is greater than in either human or cow's milk. 



Based on the results of their study, the authors suggest the following aa 

 representing, in percentages, the forms in which the constituents may be present 

 in the milk: Total solids 12.34, fat 3.8, milk-sugar 4.5, proteins combined with 

 calcium 3.1, dicalcium phosphate 0.092, tricalcium phosphate 0.0G2, dimagne- 

 sium phosphate O.OGS, trimagnesium phosphate 0.024, monopotassium phos- 

 phate 0.073, potassium citrate 0.2.5, potassium chlorid 0.16, calcium chlorid 

 0.115, and sodium chlorid 0.095. 



Analyses of 23 samples of milk from 11 goats are appended. 



The formation of protein and humin substances, L. C. Matllabd ( Geii^se des 

 Matiercs Prot^iqucs ct des Mati&rcs Unmiqucs. Paris: Masson <£• Co., 1913, pp. 

 XI +423, pis. 2). — This volume constitutes an account of the author's researches 

 on the formation of protein and humin substances. It contains an introduction 

 and four main parts, together with a general resume and conclusions. 



Experiments on the synthesis of polypeptids, peptones, and proteins by 

 means of enzyms, E. Addekiialdex {Fermcntforsch., 1 {1914*, ^^>- 1, PP- -}7- 

 54)- — ^After obtaining negative results in an attempt to synthesize higher 

 products from amino acids through the agency of enzyms, the author claims to 

 have obtained positive results by digesting liver, kidney, thyroid, and lung 

 tissue by gastric, pancreatic, and intestinal juices for three months, after 

 which period the biuret reaction was negative in all cases. 



A 20 per cent solution of such a digested product was prepared with 

 physiological salt solution, and after being thoroughly boiled was treated with 

 its own respective organ extract and allowed to stand in the incubator for four 

 weeks. At the end of this time biuret tests were made and found to be negative. 

 The preparations were then allowed to stand for five months at room tem- 

 perature, at the end of which time biuret reactions were positive and quanti- 

 tative determinations indicated the formation of protein or interniodiate prod- 

 ucts. The experimental results strongly indicate the specificity of enzyms. 



The investigation is being continued. 

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