DAIRY FARMING — DAIRYING. 697 



The authors state that they have endeavored to incorporate thebesl and mosl pro- 

 gressive methods employed in butter making in the principal dairy countries of the 

 world, and to give such related scientific information as maj beof interesl and value. 



The scope of the treatise is indicated by the chapter headings, which are as follows: 

 Composition of milk; milk secretion; properties of milk; ferments in milk; abnor- 

 mal milk; variation of fat in milk; receiving, sampling, and grading milk and cream; 

 composite samples; creamery calculations; heating milk previous to skimming; sepa- 

 ration of cream; farm separators; pasteurization; cream ripening; starters; churning 

 and washing butter; salting and working of butter; packing and marketing butter; 

 composition of butter, and judging and grading butter. The book is well printed 

 and illustrated. 



Contribution to the knowledge and determination of volatile fatty acids in 

 palm oils and butter, 0. Jensen {Landw. Jahrb. Schweiz, 19 (1905), No. 8, pp. 

 .'.i.-, : Ann. Agr. Suisse, 6(1905), No. 6, pp. /.'/-.",<;: Rev. G6n. Lait, 4(1905), 

 No. 19, pp. '/■:; -447; 20, pp.457-464; -i< PP- 181-490; aba. in Jour. Soc. Chem. Indus., 

 94 (1905), No. 19, pp. 1025, 1026).— The author separated the volatile fatty acids of 

 cocoanul oil and butter by the fractional precipitation of their silver salts, and 

 studied their properties. 



Cocoanut oil was found to contain no butyric and hut little caproic acids, while 

 the percentages in butter, though varying greatly with different samples, were on an 

 average 3.92 |>er cent for butyric and L.88 per cent for caproic. For the detection of 

 small quantities of cocoanut oil in butter the determination of caprylic and capric 

 acids is recommended. 



A marked case of late gassy fermentation in cheese, A. Peter and M. 

 Bchneebeli ( Centbl. Bakt. [etc.], 2. Abt., 15 i 1905), No. 19-20, pp. 600-605, pis. 2).— 

 From a series of 24 Kminenthal cheeses which showed gassy fermentation after 10 to 

 14 days the authors isolated a variety of Bacterium lactis aerogenes which was often 

 present in nearly pure cultures and which was considered the probable cause of the 

 trouble. A similar result was obtained in the manufacture of an experimental cheese 

 in which this organism was used in a pure culture. 



On the influence of lactic acid on casein and paracasein, O. La\a ( MUchw. 

 Zentbl., 1 I 1905), No. 12, pp. 538-547). — The author concludes from the results of his 

 investigations that casein combines with lactic acid to form lactates. 



The lactates which contain lactic acid up to 1 per cent are insoluble in water, 

 while the lactates with higher acid contents are soluble in water. By dialysis a lac- 

 tate may be obtained which contains from 1.4 to L.9 per centof lactic acid. By pre- 

 cipitation with mineral salt from a solution of casein in lactic acid a Lactate may be 

 obtained which contains 7.5 per cent of acid. It is, therefore, considered that the 

 designation of the insoluble lactate as mono-lactate and the soluble lactate as di-lac- 

 tate by Van Slyke and Hart (E. S. Et., 14, p. 607) is unsatisfactory. [It may here 

 hi- noted that the more recent investigations of Van Slyke and Hart | E. 8. R., 1<>, p. 

 L018) have shown, according to these authors, that there is only one series of casein 

 compounds formed by a combination with acids, and that what they previously sup- 

 posed was a casein mono-salt was simply the base-free casein.] 



Casein lactates contain only a small amount of phosphorus, 0.45 to 0.48 per cent. 

 The spontaneous curdling of milk is explained by the formation of Lactic acid by 

 means of micro-organisms, the changing of the phosphates of milk into acid salts by 

 mean- «.f the lactic acid, the formation in the milk of both soluble and insoluble 

 lactates, and when the soluble lactate- are present in Bufficienl quantities the precipi- 

 tation of them by the mineral salts as curd. The high plasticity of the casein in 

 cheese is due to the impregnation of the casein with calcium lactate. It is consid- 

 ered probable that paracasein is a combination of casein with calcium phosphates. 

 By the influence of acids the paracasein is changed into casein and forms the same 

 lactates as the casein. 



