EXAMINATION OF CANNED GOODS 513 
salt, 1 lb. citric acid, 123 gals. of water, developed swelled cans. Bac- 
teria with the following group numbers were isolated. 
Bacillus. ... 0.0.0... cc cece eee eee eens 111. 2232033 
Bacillus... 0.0.0.0... cee eee eee ee nee 111 .2232032 
Bacillus... 0 ee ee eee 111. 2222022 
Bacillus... 0.00.0... ee ee eee 222 .1112031 
Bacillus... ... Le ence eee eee teen eens 222 .12120382 
The growth of such organisms in the finished products probably 
indicates insufficient sterilization. The gas-forming bacteria as indi- 
cated by the above group numbers are members of the colon group. 
These, undoubtedly, got onto the mushrooms during growth, since 
they are usually grown on heavily manured areas. 
Examination of Cans for Leaks. Several ingenious methods have 
been proposed. 
1. One which is widely used is to tap the end of the can. A sound 
can with a vacuum will give a characteristic ring while one which is a 
leaker with no vacuum will give a dead sound. The examination of a 
few cans of both types will show the difference. 
2. The suspected cans may also be examined for leaks by plunging 
them into hot water. If leaks are present, bubbles will be given off. 
3. The Meade tester may be used. This subjects the suspected can 
under water to a vacuum. If the can is a leaker, a stream of bubbles 
will be given off from it. 
Storage of Food in Tin Cans. It has become almost an instinct for 
people to immediately take food out of a tin can after it has been opened. 
When the housewife is asked why she does this, various reasons are 
given. One which has often been given is that ‘‘ ptomaine ’’ poisoning 
will result. Bigelow (1918) has given some definite information on this 
subject. He regards the storage of food in the tin cans after part has 
been removed as no more dangerous than storage in containers made of 
other material, since it is becoming more and more known that food 
“poisoning ’”’ is really an infection. Bigelow determined the tin 
content in progressive samples from the same tin of food and it is inter- 
esting 1o note that after fermentation had set in (pineapple) larger 
amounts of tin were dissolved. Bigelow considers that the only reasons 
which make it advisable to remove food from opened cans are appear- 
ance and economy of space secured by putting the food into a smaller 
container, 
