FOR NEW HAMPSHIRE FARMERS 



151 



Fig. 9. 



iiig. After the pipette lias 

 draiued for a minute carefully 

 bloAv the last drop from it, and 

 the sample will be read}" for the 

 acid. 



ADDING THE ACID 



Sulphuric acid is a deadly 

 poison. It will also destroy 

 <?lothing, and char wood and 

 other substances with which it 

 comes in contact. Its use in 

 testing milk seems quite neces- 

 sary, however, and there need 

 be no trouble resulting from its 

 use if one realizes at the start 

 that it must be handled with the 

 utmost care. The common com- 

 mercial acid is used in testing, 



and it. should have a specific gravity of 1.82 or 1.83. It 

 should be used at a temperature ranging from 50 to 70 degrees 

 Fahrenheit, kept in a tightly stoppered bottle plainly labeled 

 "Poison," and put in a place beyond the reach of children. 

 Care must be taken in mixing acid wdth milk; 17.5 cubic cen- 

 timeters are measured in the small jar (Fig. 4), or with the 

 safer automatic acid measure (Fig. 10) which should form a 

 aprt of the testing outfit, and this amount of acid is then 



slowly turned into the test tube. The 

 acid should be allowed to run down on 

 the side of the bottle so as to wash 

 down any particles of milk and at the 

 same time avoid burning the milk sol- 

 ids, which will usually take place when 

 the acid is poured directly into the 

 milk. 



The acid should now appear in a 



separate layer under the milk, and 



holding the bottle by the neck a com- 



Fig. 10. plete mixture can be effected by giving 



