BAIKY FARMING — DAIRYING. 885 



The composition of milk, H. D. Richmond {Analyst, 26 {1901), No. 809, pp. 

 SIO-SIS). — The average foiiiposition of 13,798 samples of milk analyzed during 1900 

 was as follows: Specitic gravity 1.0323, total solids 12.57 per (lent, fat 3.64 i)er cent, 

 and solids-not-fat 8.93 per cient. The lowest fat content occurred during ISIay and 

 June and the highest during October and November. The fat was determined 

 usually by the Gerber method and the solids-not-fat calculated. Results i)])tained 

 in this way agreed closely in comparative tests with results obtained by the Adams 

 method for fat and the asbestos method for total solids. The chrysotile method of 

 Maclarland (E. S. R., 4, p. 983) was found unsatisfactory. 



Determinations were made of the milk sugar, proteids, and ash in a large number 

 of samples of milk to ascertain if an excess or deficiency of solids-not-fat is dne to an 

 excess or deficiency of any one of these constituents. The following conclusions 

 were reached: "Any deficiency of solids-not-fat below 9 per cent is chiefly due to a 

 deficiency in the milk sugar. Any excess of solids-not-fat above 9 per cent is chiefly 

 due to an excess of proteids. The ash may be deduced with very fair accuracy from 

 the proteids by the formula A = 0. 36 + 0. i 1 P. " 



A study was made of the relation between the proteids and salts of milk. The 

 average results of analyses of whole milk, milk serum obtained by filtration through 

 porcelain which removed all the proteids, and of whey produced by the action of 

 rennet are reported and discussed. The author considers that one-third of the base 

 with which casein is combined in milk is soda, and also that casein forms a molec- 

 ular compound with calcium i^hosphate. 



Daily variations in the fat content of milk, M. Siegfeld {Molk. Ztg., 15 {1901), 

 No. 50, pp. 907-910) . — Determinations made almost daily for 1 year of the fat content 

 of the mixed milk of 10 ilairies, which delivered during that time from 18,000 to 

 140,000 liters of milk each, are reported in tabular form. The most common daily 

 variation was from 0.1 to 0.3 per cent. The daily variation in the milk of the two 

 largest dairies did not exceed 0.45 per cent during the year. The greatest and most 

 frequent daily variations were observed in the milk of the smallest dairies, amount- 

 ing in some cases to 1 per cent and over. Causes of variations in the fat content of 

 milk, such as the health of the cows, heat, weather conditions, changes in feeding 

 and attendants, etc. , are discussed. 



Causes of variation in the butter-fat percentages of milk and cream, G. S. 

 Thomson {Jour. Ayr. and Iiid. South Australia, 5 {1901), No. 5, pp. 445-450). — The 

 author points out that variations in the yield and quality of milk may be due to 

 methods of feeding cows, irregularity in milking, rough treatment, exposure to cold, 

 stage of lactation, etc. Results of experiments in substantiation of some of these 

 points are given. Factors affecting the separation of milk, such as temperature, 

 degree of acidity, etc., are noted. The butter returns of cream are shown to be seri- 

 ously affected by the age of the cream and by the mixing of sweet and acid samples. 

 Practical suggestions are given throughout the article. 



The relation between specific gravity, fat, and solids-not-fat in milk, 

 N. Leonard {Aiiah/.st, 26 {1901), No. S09, pp. olS, .319).— The author has deduced a 

 new formula for calculating fat from specific gravity and total solids, whicli, however, 

 is not considered as accurate as the formula previously noted (K. S. R., 12, p. 186). 



A method of determining the specific gravity of milk serum and fat, 

 E. (iiTZEiT {Milch Ziy., SO {1901), No. 33, pp. 513-515).— From, the specific gravity 

 and fat content of whole milk and of the skim milk the author has deduced fonnulas 

 for determining the specific gravity of milk serum and of fat. 



Pasteurization and sterilization of milk, H. de Rothschild {Pasteurisation et 

 stcriUsation da luit. Paris: Odare Dvin and Ch. Beranger, 1901, pp. 91, figs. 33). — The 

 different phases of this subject are discussed in detail in chapters entitled: The 

 chemistry and bacteriology of milk production and rational treatment of milk, pas- 



