824 
Journal of Agricultural Research 
Vol. V, No. 18 
In experiments 35 to 48 the carcass of another hog artificially infested 
as in the case of the hog used in experiments 23 to 34, weighing about 
125 pounds dressed, was split in halves, which were hung in two freezers 
kept at different temperatures. The same procedure as to examination 
and feeding of test animals was followed as in experiments 23 to 34. 
In experiments 49 and 50 digested meat from a trichinous rabbit, 
after washing and sedimenting with water, was inclosed in small vials, 
frozen by immersion in a freezing mixture, and the trichinae, after thaw¬ 
ing, examined on a warm stage. 
In experiments 51 to 55, a hog artificially infested as in experiments 23 
to 48 was slaughtered, and meat from the carcass inclosed in five 1-pound 
cans which were placed in the center of five barrels 28 inches high by 17 
inches in diameter at the ends and 20 inches in diameter at the middle, 
each containing about 250 pounds of pork trimmings. The head of the 
carcass was kept unfrozen in a cooler to provide material for control 
examinations and feedings. The barrels were placed in a freezer the 
temperature of which was recorded six times daily by means of a ther¬ 
mometer which had been compared with a standardized thermometer. 
The barrels were removed from the freezer after 7, 8, 9, 10, and n days, 
respectively, and allowed to thaw sufficiently to permit the removal of 
the cans of trichinous meat. Examinations of the meat were made as in 
experiment 8. White or hooded rats in lots of five or six were fed some 
of the meat on several successive days, a separate lot being fed from 
each can. 
In connection with experiments 51 to 55, it may be noted that in 
another experiment it was found that the interior temperature (deter¬ 
mined by an electrical thermometer) of a barrel containing 250 pounds 
of pork trimmings did not fall to the temperature of the freezer (5 0 to 
7 0 E.) from an initial temperature of 32 0 until the barrel had been in 
the freezer for eight days. 
In experiments 56 to 64 the carcass of the hog from which meat was 
taken for use in experiments 51 to 55 was hung in the same freezer, and 
portions were removed from time to time for examination and feeding of 
test animals, following the same procedure as in those experiments. 
In experiments 1 to 64, specially reared white or hooded rats were 
used as test animals whenever possible, but in some cases it was necessary, 
on account of the lack of a sufficient supply, to utilize rats whose previous 
history was not fully known; and in other cases the use of guinea pigs 
was necessary. In the remaining experiments, 65 to 127, only white or 
hooded rats were used which had been specially reared for the purpose 
on food from which there was no possibility of acquiring an accidental 
infection with trichinae. 
The meat from six hogs was used in experiments 65 and 65a. Four 
of these were artificially infested hogs which had been fed with trichi¬ 
nous pork several months before they were slaughtered, in October, 1914. 
