DAIRY FARMING DAIRYING. 



531 



from L'20.7 to 232.C, averaging 225.3. The rauge of these samples in 

 compositiou was as follows: 



liange in tomposition of butter samples. 



Average. 



Water 



Fat 



Proteids... 

 Milk sugar 

 Ash 



Per cent. 

 9.920 



87. 550 



1.230 



.530 



.176 



The high average acidity is attributed to the fact that a large 

 proi)ortiou of the samples were conntry butter. 



The cause of the curdling of milk in thunderstorms, II. Gerst- 

 MANN (Electrotech. Ztschr., 1896, p. 74; abs. in Milch Ztg., 25 {1896), JSFo. 

 37,1). J<^^)- — The statement is made that every flash of lightning causes 

 an induction current in the milk, which decomposes the constituents 

 soluble in water. The acid suddenly developed by this curdles the 

 milk. In support of this view the rapidity with which milk often 

 curdles is noted. No experimental evidence is presented. 



Studies on milk preservatives, J. B. Weems and W. H. Heile- 

 MAN {loica 8ta. Bui. i>^^, pp. 499-501). — In numerous trials a 40 percent 

 solution of formic aldehyde was compared with corrosive sublimate, 

 l)Otassium bichromate, and no preservative. In each case 400 cc. sam- 

 ples were used and varying amounts of the preservative formic aldehyde 

 were used alone and mixed with methyl alcohol. The number of days 

 before the samples curdled was noted and frequent tests were made 

 with the Babcock test for fat. The latter showed no loss of fat due to 

 the preservative. The results of the trials are tabulated. A summary 

 is given below. 



"(1) From the above experiments there is reason to believe that 'formic aldehyde 

 40 per cent' promises to become a preservative for composite samples ; while indicat- 

 ing that it has good preserving jiowers, it has in its favor the following facts: It is 

 not poisonous, though it may l>e disagreeable if taken into the mouth in its strongest 

 form. It is readily measured and handled. 



"(2) One cubic centimeter gives premise to be sufficient to preserve the usual quan- 

 tity for the time that a composite 8ami)le is usually kept at ordinary temperatures, 

 while 2 cc. insures the sample during very warm weather. 



"(3) The condition of samples with formic aldehyde 40 per cent appears to be 

 much better for testing than those preserved by other substances. In some cases the 

 casein appears to be less readily soluble in the acid, but this is during the tirst ]ior- 

 tion of the experiment, while after keeping for some time this disappears and then 

 there is a favorable comparison with the other samples." 



Milk testing, C. L. Penny {DeUdvare Sta. Fpt. 1895, j^P- 199-206).— 

 The difl'erence between paying for milk by weight and by test is illus- 

 trated by the record of a creamery in the State for the month of Decem- 

 ber, 1894. In this the milk is valued at $1,034 per 100 lbs. and the fat at 



