1917] DAIRY FARMING DAIRYING. 875 



formation now available be placed in the liands of all wlio are responsible 

 for the laws and ordinances governing the production, transportation, handling, 

 and sale of milk." 



The advantages of a carbohydrate medium in the routine bacterial ex- 

 amination of milk, J. M. Sheeman (Jour. Bad., 1 (1916), No. 5, pp. Jf81-488. 

 pis. 2, figs. S). — A study is reported of bacterial counts made on plain agar 

 prepared according to the standard formula and on lactose agar with the same 

 ingredients plus 1 per cent of lactose. Triplicate plates were made for each 

 dilution and the counts were made after 48 hours' incubation at 37° C. 



Results obtained from 18 samples of raw market milk showed an average 

 increase of 43 per cent in the counts obtained with lactose agar over those 

 obtained from plain agar. Fourteen of these samples showed an increase of 

 over 20 per cent in favor of lactose agar. Data obtained from the examination 

 of six samples of pasteurized milk showed increases of 141 to 1,050 per cent 

 in favor of lactose agar. The average diameter of the ten largest colonies 

 on plates from one culture of Bactervum lactis acidi was 64 /i on plain agar 

 and 614 /i on lactose agar ; for another culture of this organism 284 /x on 

 plain agar and 883 n on lactose; and for a streptococcus 228 /i on plain agar 

 and 536 /x on lactose. 



The carbohydrate medium was found to be of considerable value in dif- 

 ferentiating the types of organisms on the plates. 



A. T. C. classimeter, A. T. Chabbon (Rpt. Min. Agr. Prov. Quebec, 1916, pp. 

 91-94, figs. 4). — A simple apparatus for the rapid classification of milk and 

 cream on the basis of acid content is briefly described and directions are 

 given for its use. 



The effect of feeding on the composition of butter: Decorticated groundnut 

 cake and decorticated cotton cake, H. T. Cbanfield (Analyst, 4i (1916), No. 

 488, pp. 3S6-339). — Experiments carried out at the Midland Agricultural and 

 Dairy College upon the effects on the composition of butter of feeding peanut 

 cake and cottonseed cake are reported. Analyses are given of the two cakes. 



Eight cows were fed for five weeks a basal ration of mangels, hay, bran, and 

 dried yeast. In addition 4 of the cows were fed 4 lbs. of decorticated peanut 

 cake and the others 4 lbs. of decorticated cottonseed cake per head daily. The 

 fat of the butter made from the mixed milk from each set of cows, taken night 

 and morning on alternate days, was subjected to analysis. 



No great differences were found in the composition of the butter fat produced 

 by the two groups except in the proportion of unsaturated fats, which ap- 

 peared to be somewhat greater in the samples of butter produced from the 

 peanut cake feeding. The butter from peanut cake feeding was much softer 

 and usually rather darker in color than that from cottonseed cake. No special 

 differences were noticeable in flavor of the two butters. 



Why gelatin is required and its effect on quality [of ice cream], O. E. 

 Williams (Milk Dealer, 6 (1917), No. 5, pp. 18-21) .—Brief consideration is 

 given to the use of gelatin in ice cream making, together with results of ex- 

 periments conducted by the Dairy Division of the U. S. Department of Agri- 

 culture relative to the effect of gelatin on the quality of ice cream. 



It was found that in some cases gelatin produced undesirable aftertastes. 

 Some grades of gelatin seemed to accelerate and blend the cream and fruit 

 flavor of the ice cream. Where too much gelatin was used the fruit flavor 

 was not so pronounced. Gelatin that had been heated repeatedly produced ice 

 cream having a weak body. The best results were secured when the gelatin 

 was used the same day it was prepared and at a temperature of at least 

 160° F. before it was mixed with the cold cream. 



