826 
Journal of Agricultural Research 
Vol. V, No. 18 
equal quantity of meat from each hog. Two of the cans were placed 
in freezers, one maintained at — 9 0 to o° F. (three readings daily; ther¬ 
mometer not compared with a standardized thermometer), the other 
maintained at io° to 12 0 (three readings daily; thermometer com¬ 
pared with a standardized thermometer). When removed from the 
freezers, the cans were thawed at room temperature, the thawing of the 
meat from the can taken from the second freezer (io° to 12 0 ) being has¬ 
tened by pulling the pieces of meat apart (experiment 71). The exami¬ 
nation and the feeding of test animals were carried out in the same 
manner as in experiment 65. The three other cans were placed in the 
center of boxes 28 by 19 by 6*4 inches, each containing about 100 pounds 
of pork trimmings. These boxes were placed in the same two freezers 
as the loose cans, two in the freezer maintained at the lower tempera¬ 
ture (experiments 67, 68), the third box in the other freezer (experiment 
70). When removed from the freezer, the boxes were allowed to thaw 
for two days. The cans were then removed and the meat examined 
and fed to rats, following the methods used in experiment 65. 
In experiments 72 to 76 meat was taken from an artificially infested 
hog which had been fed trichinous meat several months prior to its 
slaughter in November, 1914, and this meat was inclosed in five half- 
pound tin cans. A ham from the carcass was kept unfrozen, at first in 
a cooler and afterwards in an ice box, to provide material for control 
examinations and feedings. Two of the cans were placed in a freezer 
maintained at a temperature of — 9 0 to 2 0 F. (three readings daily; 
thermometer not compared with a standardized thermometer), two in 
a freezer maintained at a temperature of io° to 13 0 (three readings 
daily; thermometer compared with a standardized thermometer), and 
the fifth in the center of a box 28 by 19 by 6*4 inches, containing about 
100 pounds of pork trimmings, this box being placed in one of the 
freezers ( — 9° to 2 0 ) just mentioned. 
The meat in the loose cans was allowed to thaw rapidly when removed 
from the freezers; that in the box required two days to thaw so that 
the can could be readily removed. The same methods of examination 
were followed as in experiment 65, except that some of the examina¬ 
tions were made in a 0.6 per cent salt (sodium chlorid) solution fol¬ 
lowing digestion of the meat, the digested meat in those cases being 
washed with a 0.6 per cent salt solution instead of water. The use of 
a 0.6 per cent salt solution was adopted when it was discovered that 
trichinae digested out of meat commonly become inactive if kept from a 
half an hour to several hours in water at a temperature of 32 0 to 40° C. 
This does not occur in cold water nor in warm salt solution. In the 
earlier experiments the use of plain water probably led to no misleading 
results, however, as every examination was controlled by an examination 
of unfrozen meat similarly treated. The same methods with reference 
to the feeding of test animals were followed in experiments 72 to 76 as 
