488 



STATE BOARD OF AGRICULTURE. 



This bile agar did not prove to be a successful differentiating medium 

 for any of the lactic organismsi except Bad. lactis acidi (lab.). 



In only two tests in Table III was the purpose of these tests accom- 

 plished, Nos. XIX and XX, in which the typhoid germs (also the lactic) 

 were killed somewhere within 91 hours at 63°-67° acid. 



These results, however, were utilized later, in further experiments. 



A summary of Tables I, II, and III, with regard to the decrease in the 

 typhoid content is found in Table IV; with regard to the total destruc- 

 tion of the typhoid bacteria, in Table V. 



The typhoid bacilli were all killed in the experiments noted in the 

 following table: 



TABLE V. — Total Destruction of Typhoid Bacteria. 



Number of test. 



III.. 

 V... 

 VI.. 

 VIII 

 IX.. 

 XIV 

 XIX 

 XX. 



Time after inoculation. 



40i hours 

 43 hours . 

 23J hours 

 46^ hours 

 47 hours . 

 23 hours . 

 91 hours . 

 91 hours . 



Acidity of 



milk at the 



time specified. 



73° 

 75° 

 79° 

 68° 

 70° 

 66° 

 63° 

 67° 



The time element in the foregoing tests seems the most pertinent in 

 comparison with the total extermination of the typhoid bacteria in the 

 milk. In only two tests, Nos. VI and XIV, are the typhoid bacilli killed 

 within 24 hours. In test No. Ill, there is a possibility of their having 

 been killed in 221^ hours; in test No. V, the milk was not plated until 

 43 houre had elapsed; in lest No. VII, the acidity had not risen high 

 enough at the end of 23 hours to kill the typhoid organisms; it prob- 

 ably rose in a short time from G2° to 68°, but was not plated until 461/2 

 hours had elapsed; all the typlioid bacilli wore j)robably killed a few 

 hours after the milk reached 68° acid. In the ninth test, practically the 

 same conditions existed as in the preceding one. 



