800 
CONTRIBUTIONS TO OUR KNOWLEDGE OF 
MICRO-ORGANISMS AND STERILIZING 
PROCESSES IN THE CANNING 
INDUSTRIES. 
In a paper read before the Society of Arts 
in October, 1896,* we showed the extent 
of the canning industry in this country, 
and the importance to it of accurate knowl- 
edge of the bacteriological principles of 
sterilization. In that paper we dealt with 
the packing of clams and lobsters, and 
described some of the bacteria which are 
active in the deterioration of these products 
in case sterilization is not complete. It is 
interesting to notice that some of the results 
which we published at that time have lately 
been confirmed by a specialist employed by 
the Canadian government} to investigate 
the discoloration of canned lobsters. 
We now desire to put on record a pre- 
liminary account of our more recent investi- 
gations in another branch of the industry, 
viz., the packing of sweet corn. This art 
constitutes a very large industry, as is 
shown by the fact that in 1895 72,000,000 
two-pound cans (72,000 tons) were packed 
in the United States. The growth of the 
business has been rapid, for it was not un- 
til about 1853 that corn was packed at all 
with success. 
Sweet corn, when properly prepared, is 
one of the most valuable of all canned foods, 
as if retains much of its original flavor, 
is popular, and is sold at a price within the 
reach of all. If, however, the sterilizing 
has not been thoroughly done there may 
result fermentations caused by bacteria 
which have not been killed, producing what 
is known as ‘sour’ corn. 
Our investigations commenced in Febru- 
ary, 1897, with the examination of a large 
number of caus of sour corn. On opening 
the cans no change was noticeable to the 
* Technology Quarterly, Vol. X., No. 1. 
+ Supplement No. 2, 29th Annual Rep’t, Depart- 
ment of Marine and Fisheries, Ottawa, 1897. 
SCIENCE. 
[N. S. Vou. VI. No. 152. 
eye, the corn appearing fresh and of a 
natural color. In some cases a sour odor 
could be detected, but in others this was 
not observed. It was to the taste that the 
trouble was most apparent, the corn being 
sour and of a peculiar, astringent flavor. 
Bacteriological examinations showed sound 
cans to be sterile, while spoiled cans in- 
variably gave evidence of bacterial action. 
Pure cultures of six species were obtained, 
of which five were bacilli, and one was a 
micrococcus. By inoculating sterile cans 
of corn with these organisms we have been 
able to produce souring in all respects 
similar to that of the spoiled cans from 
which they were originally taken. 
In order to study these fermentations 
more thoroughly and to ascertain, if pos- 
sible, the source of the bacteria causing 
them, we spent nearly the whole of the corn- 
packing season of 1897 at an establishment 
in Oxford county, Maine, where every con- 
venience for scientific study of the process 
was put at our disposal by the proprietors. 
We were thus enabled to thoroughly in- 
vestigate the methods of procedure from 
the harvesting of the green corn to its 
ultimate shipment in cans. It is very 
necessary that the utmost cleanliness and 
dispatch should be observed in all the 
operations, so that the chances of infec- 
tion from bacteria may be reduced to a 
minimum. In this factory the strictest 
caution was exercised in these respects, 
everything being kept scrupulously clean. 
The corn is generally picked in the morn- 
ing, and is delivered to the cannery as early 
as possible. One or two men make it their 
special duty to visit the farms once or twice 
a week during the season to keep informed 
as to the condition of the crop and to ‘ order 
in’ the corn as it becomes sufficiently ma- 
tured. As the ears are delivered at the 
factory they are arranged in low piles on 
the ground in an open shed to protect them 
from the sun. The husks and the silk are 
