8o Report of the Department of Bacteriology of the 



seasons peas are successfully handled at a temperature below that 

 necessary to destroy these germs. 



How to detect quickly. — The bacillus grows rapidly at about blood 

 heat. If alive in the processed cans the fact will be shown in a few 

 days by holding samples of each day's pack at this temperature. 



How controlled. — The simplest method of control lies in raising 

 the temperature or extending the time of processing. T4ie following 

 data give the results of processing two-pound cans of peas at different 

 temperatures and for different lengths of time. In all cases cans 

 which have been previously sterilized were inoculated with large 

 numbers of the spores of the gas-forming bacillus shortly before 

 being heated. 



Two Pound Cans of Peas Heated to 230° F. at Laboratory. 



Time in minutes. . 

 No. cans heated. . . 

 No. cans swelled. . 

 Percentage swelled 



40 



3 

 o 

 o 



The number of cans used in this experiment was too small to give 

 more than a general idea of the effect of processing at 230° F. for 

 various lengths of time. The temperature of 230° F. for 30 minutes 

 had been tried on a large scale at a factory where the gas- forming 

 bacillus was present. The loss was approximately 90 per cent. 



Two Pound Cans of Peas Heated to 236° F. at Laboratory. 



Time in minutes. . . 

 No. cans heated. . . 

 No. cans swelled.. 

 Percentage swelled 



45 

 -24 



This table is the combination of the results of four separate trials. 

 The irregularities in the results obtained by processing at 236° F. 



