236 Bulletin 158. 



maxiniuni amount of gas produced is ^b of the capacity of the 

 closed arm. 



(3) One per cent saccharose houil/ou. — The liquid in the open 

 arm of the fermentation tube becomes decidedly clouded but 

 remains alkaline in reaction. In the closed arm the liquid in 

 the upper part remains clear and that in the lower third becomes 

 very feebly clouded. Gas is not produced. 



The analysis of the gas gives the ratio of the gas absorbed (CO J 

 by sodium hydroxid to the explosive residue (H) as i : 2. This 

 ratio holds true for the gas produced in both the glucose and 

 lactose bouillons. 



During the eighteen months that this organism has been under 

 artificial cultivation, there has taken place a diminution in the 

 amount of gas evolved in the fermentation tubes containing the 

 sugar solutions. At present, only about one-fourth of the quan- 

 tity of gas originally produced is formed. 



Thermal Death Point. — This organism is destroyed in freshly 

 inoculated small tubes of bouillon when exposed to a temperature 

 of 60° C. for ten minutes in a closed water bath. 



Resistance to drying. — Drops of a bouillon culture placed on 

 sterile cover-glas.ses under a bell jar, retained their vitality tor 

 sixty da3'S. 



Indol 7'eaction. — A strong indol reaction was obtained in 48-hour 

 cultures in Dunham's peptone solution. 



Prodiiction of the taint. — A quantity of market milk was divided 

 into two equal parts w^hich were placed in the two divisions of a 

 double cheese vat so that each might be made into cheese under iden- 

 tical temperature conditions. To one of these quantities of milk, 

 about 100 lbs., was added two quarts of a 24-hour milk culture of 

 the bacillus. Shortly after adding the culture, a " tainted " odor 

 was observed in the milk of the one vat only. During the pro- 

 cess of cheese making the odor in the inoculated vat was 

 observed to become progressively more intense. The curd in this 

 vat became distended with gas to such an extent that it floated 

 upon the whey. 



Identical results were obtained during the 1898 session of the 

 Dairy School. The milk used in this experiment was taken from 

 the mixed milk with which the other vats were supplied. 



