teria were used. This type of organism is more resistant to heat and 

 thus would be of more practical value in the experiment. It is also 

 found the greatest number of times in canned salmon. The follow- 

 ing bacteria were used: B. alholactus, B. vulgatus, B. mycoides, B. 

 sporogencs, B. botulinus, B. ccreus, B. pseudotetanicits. Hunter and 

 Thorn's bacillus (B. mcsentericus, Fliiggc), a thermophile, and soil 

 from the street. 



Canning. White king salmon were obtained from local whole- 

 sale fish dealers, which had been caught in the waters of Alaska 

 by trollers, iced, and then shipped to Seattle, At the time of canning, 

 the fish were at least a week old, and perhaps older, but as they had 

 been kept at a comparatively low temperature they were in very good 

 condition. All the canning was done in the canning laboratory of the 

 College of Fisheries, University of Washington, Seattle. After being 

 thoroughly cleaned, heads removed as well as fins and viscera, the fish 

 were hand packed in one-half pound flat sanitary salmon cans. 



Inoculation of cans. In inoculating the cans a short wire was 

 smeared over the cuture prepared and thrust into the meat as near 

 the center of the can as possible. Reasonable care was taken to ward 

 ofif any contamination. Eighty-eight cans were filled and inoculated, 

 40 cans on April 8 and 48 cans May 13, 1921. As a control, 8 of 

 the latter, two for each temperature, were not inoculated. Each kind 

 of bacteria was inoculated in eight different cans. All the cans were 

 then exhausted for 15 minutes at 212° F. with the top on loosely 

 (clinched). After exhausting they were double-seamed and proc- 

 essed, two of each inoculation for 45 minutes, two for 60 minutes, 

 two for 75 minutes, and two for 90 minutes, all at 240° F. 



By varying the time factor and keeping the process temperature 

 the same, but one variable element entered into the experiment. In 

 selecting the time factors, 45 minutes was taken because it was 

 thought with good reason that this length of time was entirely too 

 short and would give a basis for comparison. Sixty minutes was 

 thought to be just a little under normal ; 75 minutes was thought suf- 

 ficient, and 90 minutes too long. In short, there were selected two 

 lengths of time thought to be too short, one too long, and one about 

 normal. After processing, the cans were allowed to cool naturally. 



Method of examination. In examining the cans of salmon, an 

 attempt was made to isolate all the types and species of organisms 

 found to be present, and learn their relation to the bacteria originally 

 inoculated in the cans. It should be kept in mind that some bacteria 

 were in the salmon from the start. The scheme adopted is the one 

 worked out by Dr. Weinzirl, of the University of Washington, and 



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