NATURAL StrARATIOX OV CRhAAI AND .MILK 



n 



1.020 — 



F 



1.025 — 



,n 



10 — 



20 

 30 

 40 



SO- 



90- 



100 : 



specific gra\-it}- into lactometer reading the re\'erse proccis will 

 give correct results. 



The hydrometer gives the specific graAdty directly. The 

 Board of Health lactometer has a special graduati<jn. When 

 this lactometer was devised it was thought that 1.029 was the 

 minimum specific gra\1ty of un- 

 adulterated milk. The scale on this 

 lactometer was made from zero 

 to 120, zero marking the point which 

 represents the specific gra^•it^- of 

 water, namely, i, while 100 is the 

 point which is assumed to represent 

 the least specific gravit}- of milk, 

 1.029. If the specific gra^■it\- of a 

 certain sample of milk fell to 90, it 

 indicated that there was 10 per cent 

 of water present. If it fell to 80, 

 it indicated that there was 20 per 

 cent of water, etc. 



In order to calculate the total 

 solids, and solids not fat, of milk, 

 it is necessary to know its lactometer 

 reading, and the percentage of fat 

 in it. Knowing these factors, b}' 

 the use of the following formula 

 given by Farrington and WoU, and 



20 — 



C 



S N Q 



Specific Gravity Scale, 



deduced from Fleischmann's work, ''5',', ^^™ ^°'^ ^"'"'• 



Q Quevenne. 



the total solids, and sohds not fat 

 can be found. 



Fig. 4. — Comparati\"e gradua- 

 tion of lactometer stems. 



Sohds not fat = j fact. reading + .2 times the fat. 

 Total solids = fat -|- sohds not fat. 



Natural Separation of Milk and Cream. — When milk is 

 allowed to stand quieth' for a short time, a la}"er ha\'ing a rich- 

 3'ellow color comes to the surface. This is the cream, and con- 

 tains most of the fat. This separation is due chiefly to the 



