SPECIFIC GRAVITT OF CREAM. 221 



The specific gravity of cow's milk is said to be 

 lighter than milk but denser than water, by Dr. 

 Voelcker,'^ who gives the following as the result of 

 his trial, and Willard'^ accepts these results. 



From milk after standing 15 houra 1019.4 at 62° 



" " is " 1012.7 " 62° 



" " " 48 " 1012.9 " 62° 



Letheby, in his Lectures on Food,''' states the spe- 

 cific gravity at 1013, while Berzelius'^ places the 

 specific gravity of cream at 1024.4, the figui'es which 

 are accepted by Dr. Golding Bird.'^ L. B. Arnold,'^'' 

 of Rochester, N. Y., states that cream has the specific 

 gravity of 985. 



In my own experiments I have usually found that 

 a drop of cream, carefully dropped on rain-water, 

 would float. It even floats when dropped into the 

 water from a height, so that the force of the impact 

 carries the drop below the surface or spreads it on 

 the surface. In one instance only have I known the 

 cream to sink when carefully placed on the surface of 

 rain-water. 



Experiment VIII. 



lu one carefully-conducted experiment made with 

 the cream from the surface of a large cream-jar, 

 1 found the specific gravity to be 983 at 62° by 



15 Journ. E. A. S. of Eng. 1853, pp. 298, 317. 



ic Dairy Husbandry, p. 168. 



1' Ibid. p. 34. 



18 Johnson's Farmers' Enc. pp. 240, 814. 



i» Cooper's Anat. of the Breast, p 119. 



2» Am. Dairyman's Ass. Trans. 1870, p. 160. 



