376 Journal of Agricultural Research vol. xx, no. s 



temperatures of incubation. The number of samples, as well as the 

 urgency of the examination, however, forbade any elaborate series of 

 tests. The total number of cans and glass jars, both normal and spoiled, 

 which were cultured by various members of this laboratory, together 

 with the number showing the presence of living organisms, is summar- 

 ized as follows: 



Experiment with cans 

 Exp. No. 



I. Number of normal cans cultured 181 



Of this number 173 were sterile, while 8, or 4.4 per cent, were found to 

 contain viable microorganisms. 



II. Number of "swelled" or "springy" cans cultured . . 157 



Of these 154 contained living microorganisms, while 3 were apparently 

 'sterile (2 of these 3 were "springers," the other was a "hard swell"). 



Total number of cans cidtured 338 



Experiment with glass containers 

 Exp. No. . . 



I. Number of containers normal in appearance and odor 116 



Of this number 105 were sterile, while 11, 'or 9.5 per cent, revealed the 

 presence of living microorganisms. 



II. Number of containers obviously spoiled or of bad odor 26 



All of these 26 gave positive cultural results. 



Total number of glass containers cultured 14 2 



Total number of cans and glass containers cultured 480 



Thus, it is seen that all the obviously spoiled glass jars, and, with one 

 exception, all the swelled cans revealed the presence of living micro- 

 organisms. On the other hand, the normal containers were, for the 

 most part, sterile. In this connection it is interesting to note that 4.4 

 per cent of the normal cans were found to contain viable organisms, 

 while in the normal glass containers the proportion was decidedly higher, 

 namely, 9.5 per cent. Of the 157 swelled or "springy" cans, all but 

 three gave positive cultural tests. Two of these three were "springers," 

 due probably to imperfect exhausting, and were no doubt otherwise 

 normal. The third was a "hard swell." Whether the failure to obtain 

 living organisms from this one can was due to lack of a greater diversity 

 of culture media or whether the causative organisms had been killed as 

 a result of their own metabolic products is not known. 



Of the total of 480 containers examined bacteriologically, 117 of those 

 which had yielded positive cultural tests were studied further to gain some 

 knowledge of the types of organisms present. As a rule, extensive cul- 

 tural and biochemical tests were omitted, and merely the general type or 

 group to which the organisms belonged was determined. A summary 

 of the types obtained from the 1 17 containers thus studied is shown below. 

 The figures indicate the number of times each was encountered. 



