300 



STATE BOARD OF AORICULTURE. 



weeks, when (lie reiiction clianjjod to alkaline. This peculiar behavior. I am inclined to 

 think, probably explains the behavior of cheese which at first does not possess any 

 marked taint, but upon standinj,' the disajireeableness of the odor becomes pronounced. 

 Hither there is not sullicient acid maintained to cheek other niicro-orji^ani.sms of the 

 .saprophytic class from institutin<i; sli^'lit decomposition of the casein, or this germ 

 itself, {irown under conditions which furnish an abundance of nitroj^enous food but 

 little carbohydrates in the form of lactose, gives rise to odoriferous products. I am 

 inclined to the latter belief because of the fact that at first this germ produces no 

 unpleasant odors when cultivated in the presence of carbohydrates, but after the 

 carboliydrate fermentation ceases there is perceptible a distinct unpleasant odor. 

 There could not be detected, however, any j)roteolytic action. Qualitative tests made 

 for alcohol and acetic acid resulted in a failure to detect even traces when the bacillus 

 was cultivated in milk cultures; lactic acid seemed to be the principal stable product. 

 The acidity was not materially reduced by distillation and then making up the amount 

 remaining in llask to original amount by the addition of water. Lactic acid was also 

 found in glucose bouillon cultures. 



. K 



Ir ' 





' r^ 



>^. 



■ ■"- ^^£:i3m'iimm0mstmsimms:^!i;mm^'msi'pmis^'- 



Fig. 2. [No bacterial starter.] 



Upon investigating the nature of the gas produced, a rubber tube filled with water 

 connected the fermentation tube with a Hempel's gas burette. The amount of gas after 

 standing for some time measured 99.1 c. cm. The burette was then connected by 

 means of a capilliary tube with a Hempel's pipette containing potassium hydroxide. 

 The gas was run into the pipette and the carbonic acid gas absorbed by shaking. When 

 the remaining gas was returned to the burette, the volume of gas left measured only 

 22.14 c. cm. This was then passed into a Hempel's pipette containing alkaline pyro- 

 gallic acid and thoroughly shaken. When returned to burette the measurement, 

 22.14 c. cm., was the same as before passing into the pipette. Evidently no oxygen 

 existed in the gas. The gas was again passed into the pipette over palladium asbestos 

 to absorb the hydrogen by converting it into water. 16.96 c. cm. of the gas was disposed 

 of in this manner. There remained unaccounted for 5.18 e. cm. of gas, which is neither 

 carbonic acid gas, oxygen nor hydrogen. Its nature has not been determined. There- 

 fore, out of 99.1 c. cm. of gas produced by this micro-organism, 76.96 c. cm. was 

 carbonic acid gas, 16.96 c. cm. hydrogen and 5.18 c. cm. unaccounted for. In another 

 determination where 52 3-5 c. cm. of gas was used, there proved to be 26 3-5 c. cm. 

 of carbonic acid gas and 20 3-5 c. cm. of hydrogen, leaving 4 4-5 c. cm. undetermined. 



