old FOOD PRESERVATION 
10 cents. This applies to soup, beans, etc. Table L gives the sizes and vol- 
umes of the standard cans. 
TaBLe L 
SHOWING THE SIZES AND CAPACITIES OF STANDARD CANS 
(After Bitting) 
Number Diameter in Inches Height 1n Inches Caparity in Ounces 
i oi 4 12 
2 3%, 43%, 22 2 
22 4y5 43 32 6 
3 43 4? 36 4 
10 675 7 116 1 
Under domestic conditions, glass cans have been much used. Great 
care, however, has to be used to secure a tight seal, which is often ren- 
dered difficult on account of poor rubber gaskets. 
Swells. According to Bigelow (1914) a “‘ swell” is a can which 
has undergone decomposition by microorganisms accompanied by 
generation of gas, which first releases the vacuum and then causes 
pressure in the can. This decomposition is often of putrefactive nature 
and may be rapid or slow, according to the organisms and temperature. 
They are caused by different factors. Insufficient sterilization or leaky 
cans are evident causes. One leaky can may infect other cans in a 
similar condition. 
Baker (1912) has given some attention to the composition of gases 
occurring in commercial canned foods. Some of the analyses given 
below are taken from his paper: 
Can of red raspberries, eighteen months old: 
Per Cent 
Carbon dioxide... 0... 2... ccc ccc cee tent e ee 8.40 
OXYZON eee eet ee eens .00 
Hydrogen. ... 0.0... ccc cece tee cece eee neee 65 50 
Nitrogen... 0... ee tt tect e eee en 26.10 
Can of strawberries, eighteen months old: 
Per Cent 
Carbon dioxide. ........ 0.0 cece eee cece neces 12.60 
OXYBEN. ce ce ee eee eens 00 
Hydrogen... 2... ccc cece eee eeu eees 72.40 
Nitrogen. ..... 0. cece cece cee cee eee eee enees 15.00 
