170 



TEAGUE AND BARBER. 



In the cold storage room the spraying continued from lO.SSJ to 10.56 a. m. 

 The temperature of the room was as follows: At 11.02, 20 °C.; at 11.30 a. m., 

 19° ; at 12.35, 18°. Then it remained at 18° until the end of the experiment. 



Table III. — Showing growth of colonies. 



Time after 

 spraying. 



B. prodigio- 



sus in dry 



hood. 



B. prodigiosiis 

 in wet hood. 



B. prodigio- 



sus in cold 



room. 



Hrs. min. 

 1 

 5 

 10 

 20 

 30 

 40 



50 



1 

 1 10 

 1 20 

 1 30 

 1 40 



1 50 



2 

 2 15 

 2 30 



2 45 



3 

 3 15 

 3 30 



3 45 



4 



Colonies. 



78,000 



52, 000 



19.000 



170 



1 







2 











Colonies. 



Innumerable. 



Innumerable. 



130, 000 



57,000 



22.000 



15,000 



8,500 



7,000 



4,000 



1,500 



330 



170 



50 



15 



8 



Colonies. 



44, 000 



37, 000 



19, 000 



9,500 



6,000 



4,500 



3,500 



3,000 



2,000 



2,000 



1,400 



1,300 



900 



750 



450 



300 



350 



200 



150 



150 



125 



90 



















 























As with the cholera vibrios so also in the case of B. prodigiosus 

 there is a striking difference in the length of time that the bacilli 

 remain alive in a dry and in a moist atmosphere. In the cold 

 room the bacilli remain alive in the air even longer than in the 

 wet hood. Unfortunately, the humidity of the cold room during 

 this experiment was not determined. 



I It was, therefore, necessary to perform the following ex- 

 periment. The same suspension of B. prodigiosus was sprayed 

 for one-half a minute into a moist hood and into a cold storage 

 room, and Petri dishes containing solidified agar were exposed in 

 both places for periods of two minutes each at intervals of four 

 hours. In the cold room the dry-bulb thermometer registered 

 12° C. and the wet-bulb one about 10°. 5 C. throughout the 

 experiment. In the hood the dry-bulb thermometer varied be- 

 tween 31.1 and 31.5 and the wet-bulb one registered about 0°.2 

 below the dry one. It is clear that the water deficit of the 

 atmosphere was greater in the cold room than in the hood. The 

 result of this experiment is recorded in Table IV. 



