CLARIFICATION OF MILK. 



233 



Table XLVII. — Effect of Clarification on Pure Cultures of 

 Bacteria — Concluded. 



B. noli. 



Suspended in — 



First Test. 

 Salt solution. 



Whey solution, . 



Certified milk, 



Second Test. 

 Salt solution, 



Whey solution, . 



Certified milk, 



Third Test. 

 Salt solution. 



Whey solution, . 



Certified milk, . 



Streptococcus lacticus. 



First Teat. 

 Salt solution. 



Whey solution, . 



Certified milk. 



Second Test. 

 Salt solution, 



Whey solution, . 



Certified milk, . 



Third Test. 

 Salt solution. 



Whey solution, . 



Certified milk, 



4,500,000 

 3,500,000 

 1,000,000 



700,000 

 720,000 

 600,000 



400,000 



430,000 



1,060,000 



1,500,000 



1,300,000 



800,000 



120,000 



60,000 



540,000 



35,000 



70,000 



600,000 



66 

 63 

 20 



82 

 91 

 10 



91 

 82 

 43 



Note. — 1. Salt Solution. — Prepared by adding 8.5 grams of sodium chloride to 1,000 cubic 

 centimeters of distilled water. Sterilized by autoclaving at 15 pounds for thirty minutes. 



2. Whey Solution. — Prepared from whey secured from the college dairy. Egg albumin was 

 added to the whey, and heated for two hours in the flowing steam. It was then filtered clear 

 through filter paper. To this was added 1 per cent, of bacto-gelatin and sterilized intermittently. 



3. Certified Milk. — Fresh certified milk secured from the college herd. 



4. In each of the experiments 1,000 cubic centimeters of the material was employed. The pure 

 culture under test was added directly from a twenty-four-hour mOk or broth culture, after the 

 quantity of culture to be used had been determined. 



5. The specific gravity and viscosity of the whey menstruum were approximately that of cer- 

 tified milk, as determined by preliminary experiments with pyknometer and viscosimeter. 



6. Room temperature in which experiments were conducted varied from 19* to 23° C, so that 

 clarification was conducted within this range of temperature. 



