New YorK AGRICULTURAL EXPERIMENT STATION. 55 
milky and had a sharp, acid taste. A very few cans gave evi- 
dence of a mingling of these two forms of decomposition. 
BACTERIA IN THE SWELLED CANS. 
A microscopical examination of the juice from a swelled can 
showed that there were large numbers of bacteria present, while 
a like examination of a good can failed to show any bacteria. 
Some of the sour cans contained a round or coccus form while 
other sour cans contained a rod form. The coccus form was studied 
sufficiently to show that it would not only sour cans of peas 
when artificially introduced but that when kept at blood heat 
these cans would commonly bulge. 
The vile-smelling cans which made up more than 99 per ct. 
of the trouble all contained a rod form. This was plumper than 
those observed in the sour cans and in many cases was distin- 
guished by a swelling at one end giving it the appearance oF a 
drum stick. 
BACTERIA. CAUSE THE SWELLING. 
The plump rod form having swollen ends was in many cases 
the only form to be found in the swelled cans. From such cans 
cultures were prepared at the laboratory and this germ separated 
from all other forms. A considerable number of cans of sterile 
peas were vented and a part of them received a culture of this 
germ. All were now resoldered and kept at blood heat. All of 
the inoculated cans swelled within 24 hours. In many cases the 
tension became sufficient to burst the cans. The cans which had 
been vented and resoldered without inoculation did not swell. 
An examination of the inoculated, swelled cans showed only the 
single form present. 
These facts, then, identify the causal organism: (1) The find- 
ing of large numbers of a certain species of bacteria in spoiled 
canned goods while satisfactory goods are sterile; (2) the isola- 
tion and study of this germ in pure culture; (3) the inoculation 
of sound goods with these cultures and the production of the 
original trouble; (4) the reisolation of the germ from these goods 
and (5) the determination that it is the original species. These 
points complete the cycle of proof required to establish the fact 
that the original trouble was due to the activity of this germ. 
