14 



THE NEW YORK JOURNAL OF PHARMACY 



C. U. C. P. DRAMATIC SOCIETY. 



President, J. J. Coronel. 

 Secretary, Miss Kaplow. 

 Treasurer, Miss Davidson. 

 Reporter, Miss Kleppner. 

 Meetings— Saturday at 5 P. M. 

 Immediately after, organizing, Coach 

 Hochberg began real work with his 

 charges. 



He has selected a play and the parts 

 have been assigned. Under stich capa- 

 ble directorship, the Society will, no 

 doubt, in a short time spring a surprise 

 on us all. 



SPECIFIC GRAVITY OF MILK. 



D. M. Bull, '16. 



As milk is slightly heavier than water, 

 and as water is the most common adul- 

 terant of milk, any addition of water 

 would serve to lessen its specific gravity. 



To determine the specific gravity of 

 milk we use an ordinary Board of Health 

 Lactometer. In devising the lactometer, 

 it was assumed that 1.029 was as low as 

 the specific gravity of any unadulterated 

 milk would fall, therefore the scale of 

 the lactometer was graduated from o to 

 120, the o marking the point of pure 

 water, or a specific gravity of i.ooo, and 

 100 corresponding to the assumed least 

 specific gravity of milk, or 1.029. If, 

 then, in any' given sample of milk the 

 lactometer fell to 90, it would indicate 

 the presence of 10 per cent, of water, 

 and if it fell to 75, of 25 per cent, of 

 water. 



The relative density of milk varies 

 with its temperature, so that the lacto- 

 meter is only correct at one given tem- 

 perature. Most lactometers are grad- 

 uated for a temperature of 60° F. 



The solids in milk are not all of the 

 same specific gravity ; some are heavier 

 and some lighter than water. 



The fats are lighter, the other solids 

 are all heavier. 



The specific gravity of the milk, then, 

 depends not only on the amount of solids 

 in the milk, but also upon their relative 

 proportions. 



The specific gravity may be affected 

 by the addition of any substance to it 

 or the abstraction of any of its constitu- 

 ents. Since some of the constituents of 

 milk are lighter than water, their abstrac- 

 tion in whole or in part would be fol- 

 lowed by an increase in density. 



It will be readily seen that if a part 

 of the fats are removed the specific 

 gravity of the skimmed or partly skimmed 

 milk will be heavier than normal, and 

 the addition of a certain amount of water 

 or other substance lighter than the milk 

 would only serve to bring the specific 

 gravity back to the normal point. 



In this way, if it is done skillfully water 

 may be added to milk, and cream ab- 

 stracted from it without affecting the 

 specific gravity as revealed by the lacto- 

 meter, and a very inferior sample of milk 

 might pass as perfectly normal if the 

 lactometer alone was depended upon for 

 its detection. Y"ou can readily see that 

 this method of testing milk for specific 

 gravity with the lactometer alone would 

 be very incomplete. So Prof. Babcock, 

 of Wisconsin Agricultural College, in- 

 vented the Babcock test, which gives a 

 very accurate account of the amount of 

 butter fat contained in a given sample 

 of milk, so that taking the two tests 

 together we get very close to the actual 

 amount of adulteration. 



