SPECIFIC GRAVITY OF CREAM. 221 



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

 lighter than milk but denser than water, by Dr. 

 Voelcker, 15 who gives the following as the result of 

 his trial, and Willard 16 accepts these results. 



From milk after standing 15 hours 1019.4 at 62 



" " " 43 " 1012.7 " 62<> 



" " " 48 " ....1012.9 " 620 



Letheby, in his Lectures on Food, 17 states the spe- 

 cific gravity at 1013, while Berzelius 18 places the 

 specific gravity of cream at 1024.4, the figures which 

 are accepted by Dr. Golding Bird. 19 L. B. Arnold, 20 

 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. 



In one carefully-conducted experiment made with 

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

 I found the specific gravity to be 983 at 62 by 

 weighing. 



is Journ. R. A. 8. of Eng. 1863. pp. 298, 317. 



is Dairy Husbandry, p. 168. 



Ibid. p. 34. 



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



w Cooper's Anat. of the Breast, p 119. 



20 Am. Dairyman's Ass. Trans. 1870, p. 160. 



