DAIRY FARMTNC DAIRYING AGROTECHNY. 1179 



The proteolytic enzym of human milk, A. K. Austin {Jour. Med. Research, 

 ni (I'.KhS). Ao. ,-\ iii>. .W9-J/.9).— Sauipli's (if milk from lil persons at diflerent 

 IRTiods of liRtatioii were exauiiiu'il to dt'teriniiK' why bivast milk often dis- 

 ajirees with the healthy infant. No enzynis were found by Volhard's method, 

 empoyed for tryiisin. A modification of IMetschel's method was emitloyed 

 for the determination of rest nitrogen (nonprotein nitrogen). The results 

 were v.iriable and inexplicable. 



" Before the subject here treated can be fully settled we must know more of 

 the character of this rest nitrogen, and the most attractive feature is the possi- 

 bility of the presence of amino acids." As a test for amino acid a combination 

 of Ackermann and Levene's method was employed. No free glj'cocol, alamin, 

 nor leuciu were found. The results are summarized as follows: 



" There is no evidence of autodigestion of human milk, at least under tha 

 conditions pertaining to such digei^tions in organ tissues. 



" The digestive disturbances of infants fed on human milk can have no rela- 

 tion to such an enzym. as the milk of l)t)tli healthy and sick women was 

 examined. 



" The rest nitrogen is still a riddle, though if amino acids compose a part 

 of it they are remnants of a synthesis to protein, and not products of digestion 

 of milk protein." 



On the nucleon content of human milk, A. Valenti {Arch. Fannacol. Sper. 

 c Set. Aff., 7 U-IOS). Ao. 10. i>i). .} '/7--iJ.O. ehfirts 2: <ibs. in ('hem. Zenthl.. 1909, 

 I, Xo. 2, p. 93). — The author found that the average percentage of nucleon in 

 human milk with three subjects tested three times a month was 0.1302. 0.1339, 

 and 0.1305, respectively, and appeared to vary invei'Sely with the amount of 

 milk. The maximum amount of nucleon was in the first two or three months 

 of lactation. 



On milk secretion and the microscopical testing of milk, W. Winklkb 

 (Ztuchr. Landn: ^'ersuehKW. Osterr.. 11 (1908), No. 6, pp. 562-630, pis. /,; ahs. 

 in FiihUn(/.s Landir. Ztij.. 51 {190S). Ao. 19, p. 612).— The results of a micro- 

 scopical study of milk and the tissues of the manmiary glands are reported 

 and the work of other investigators is reviewed. 



The autlior could distinguish four different cellular layers in the sections 

 of the alveolus, as follows: (1) The membrana propia, described by Fiirsten- 

 berg. which is composed of connective tissue; (2) a layer of muscular fibers 

 that can contract the alveolus and force out the secretion; (3) a merismatic 

 layer wherein nuclear division is very active during the lactation i)eriod ; and 

 (4) a layer of secretory epithelial cells. 



The author believes that fat globules have a firm membrane, and that the 

 " lactokonien " of Kreidl are granules of casein. Kancid milk may sometimes 

 be caused by irregular-shaped fat globules formed in the udder. Leucocytes 

 and lymphocytes are seldom found in milk. A distinction should be made be- 

 tween leucocytes and epithelial cells of milk. 



Slimy milk, L. Eberlkin {Pure Products. >, (WOS), No. II. pp. .'i9',-.',99).— 

 This is a review of bacteriological investigations on the causes of slimy and 

 colored milk. 



Fermentations of milk and cheese, A. Kocii {.Jdhresher. Gdruiuf.'i-Orfidnis- 

 incn, 16 ( 190.')). pi>. 259-.i.')l ). — A review of the articles on this subject for 1905. 



On lactic-acid fermentation in milk, .M. \V. Hemekinck (A'. Ahad. ]Vetenseh. 

 Amsterdam, I'roc. Sect. ScL, 10 (1901), pt. 1, pp. i 7-3.'/). —This is mainly a 

 discussion of the proi)ertles of different types of lactic-acid bacteria. 



liactic acid as an agent to reduce intestinal putrefaction, P. G. Heinemann 

 {Jour. Amer. Med. .Ls-.s-oc, 52 {1909), No. 5, pp. 312-316).— The work of Metch- 

 nikofC and other observers is reviewed. The author's investigations with steril- 



