490 EXPERIMENT STATION RECORD. 



usually free from putrid smell and miscible. The antiseptic power of this reagent 

 is well known to be very great. One-tenth per cent is insufficient to preserve milk 

 a week, but 0.3 per cent is sufficient for a month or more. . . . 



"[With 5 per cent of magnesia or magnesia mixture] the sample after 8 days 

 had a putrid smell, with a translucent substratum. Notwithstanding, it was excep- 

 tionally miscible and the final results were among the most satisfactory. Doubtless 

 much less than 5 per cent would be equally efficient. . . . 



' ' [ Formalin in proportion of 0.2 to 0.5 per cent] in point of minimum efficient quan- 

 tity is the most powerful preservative tested. Even 0.2 per cent will keep a sample 

 for weeks in excellent condition. It is questionable, however, whether this minute 

 quantity, small as it is, is without influence on the Babcock test. The mixture of 

 milk and acid has an unusual greenish appearance, and the fat column is hardly so 

 clear and sharply defined as is the case with many other preservatives.'' 



On the influence of food on the quality of butter, F. Frits (37 rte 

 Ber. K. Vat Landbohbjskale Lab. Landokon Forsbg, Copenhagen, 1897, 

 pp. 112, 190). — These experiments were conducted during -4 successive 

 years, viz, 1892-'96, with special reference to studying - the effect of the 

 various rations fed on the quality of the butter produced. Two large 

 Danish estates, well known for the high grade of butter produced, 

 furnished the cows and other facilities for the experiments. The 

 number of cows included in the different experiments on each farm 

 was, as a rule, 60, separated into 3 lots of 20 each, care being taken in 

 arranging the different lots to make them as uniform as possible as to 

 breed, age, live weight, calving time, milk yield, richness of milk, etc. 

 In all about 500 cows were included in the experiments. The effort 

 was in all cases to make a first-class product of butter or the best 

 product possible under the conditions, and the milk, cream, and butter 

 of the different lots were always treated with this end in view. Only 

 fresh cows were used, and only such of these as were found perfectly 

 normal and healthy after a rigid examination. The milk of any cow 

 showing symptoms of sickness during the progress of the experiment 

 was kept by itself, so as not to contaminate the product of the other 

 cows. 



The plan and conduct of the experiments were similar to those of 

 the cow-feeding experiments previously conducted by this station. 

 During the preparatory period, lasting 20 to 30 days, the feed of the 

 different lots on each farm was the same. The rations of all the lots 

 but one was then gradually changed during a transition period of 10 

 days to that to be fed during the experiment proper, the one lot receiv- 

 ing the same feed throughout the experiment. Ten days after the 

 experiment proper an after-feeding period followed, during which the 

 feed of the different lots was changed back to that fed in the prepara- 

 tory period. The experiments here reported included trials with the 

 following feeds: Grains (barley and oats) against rape-seed cake (ordi- 

 nary and pure, manufactured especially for the experiments), suntiower- 

 seed cake, palm-nut cake, and rape seed; mangel-wurzels against tur- 

 nips; and grains (barley and oats) against molasses feed (one eighth 

 palm-nut meal, three-eighths wheat bran, one-half beet molasses). Bay, 



