828 
Journal of Agricultural Research 
Vol. V, No. iS 
freezer and the placing of the meat in artificial gastric juice in prepara¬ 
tion for examination varied between 6 and 12 days. 
In preparing the meat for examination and feeding tests, the contents 
of the can were passed twice through a meat chopper, thoroughly mixing 
the ground meat together. Fifty gm. of ground meat from each can 
were placed in a beaker containing 600 c. c. of a freshly prepared artificial 
gastric juice made by the following formula: Water 1,000 c. c., hydro¬ 
chloric acid (sp. gr. 1.19) 10 c. c., scale pepsin (U. S. P.) 2.5 gm. (experi¬ 
ments 77, 78); or the same formula modified by the addition of 6 gm. of 
sodium chlorid (experiments 79 to 87). The contents of the beaker were 
then stirred and carefully warmed to 40° C. and the beaker placed in an 
incubator (37 0 to 40° C.) for 18 to 24 hours. After removal from the 
incubator the supernatant fluid was decanted off, salt solution (0.6 per 
cent) added, the contents of the beaker stirred, allowed to settle, again 
decanted, more salt solution added, and so forth, until the supernatant 
fluid remained clear and transparent. As a control upon a possibly 
injurious effect of the digestant on the trichinae, 50 gm. of ground un¬ 
frozen meat from the same carcasses as the frozen meat to be examined 
were placed in 600 c. c. of the same lot of digestant prepared for digesting 
the meat which had been frozen, put into the incubator, and removed at 
the same time as the other, washed in the same manner, and handled in 
all respects exactly the same as the meat which had been frozen. The 
sediment which remained in the beakers after washing and decanting was 
examined in salt solution (0.6 per cent) on a warm stage under the 
microscope. 
In the tests on animals five white or hooded rats, reared from birth on 
food from which there was no possibility of acquiring an accidental infec¬ 
tion with trichinae, were used for testing each lot of meat. The five rats 
were kept together in a cage and 50 gm. of the ground meat were placed 
in the cage each day for three days, a total of 150 gm. of meat, or an 
average of 30 gm. per rat. The cage was watched to see that the meat 
was all eaten. It was usually eaten promptly. The rats which died 
within the first two weeks were examined for the presence of trichinae in 
the intestine as well as in the muscles. In the case of those which died 
later only the diaphragm was examined. A month or more after feeding, 
the surviving rats were killed, and their diaphragms were examined. 
Through an oversight no control animals were fed with unfrozen meat 
from the five hogs from which the meat was obtained for use in this set 
of experiments (77 to 87). In view of the undoubted viability of the 
trichinae in these hogs, however, as determined by the fact that the 
trichinae obtained from digested unfrozen meat were practically all 
active, very lively, and quite normal in all respects, this omission is not 
of great importance. 
In the next series of experiments (88 to 90), meat was taken from the 
shoulders of seven naturally infested hogs slaughtered during December, 
