840 
Journal of Agricultural Research 
Vol. V, No. i3 
The results of these experiments show that temperatures of about 
5 0 F. have a profound effect upon the vitality of trichinae. Only a 
very small proportion survive an exposure of more than five days, and 
these are so seriously affected that infections are extremely unlikely to 
occur, none having resulted in any case in which test animals were fed 
meat exposed to temperatures of about 5 0 for periods ranging from 6 to 
23 days (19 experiments). \ In view of the results of experiment 68, 
however, in which the temperature was — 9 0 to o° and the period of 
exposure 10 days, it may be concluded that slight infections may some¬ 
times result from meat exposed to 5 0 for as long as 10 days. 
The results of the experiments with temperatures of about 5 0 F. corre¬ 
spond closely to those of Schmidt, Ponomarer, and Savelier (1915). 
These authors, however, found that in their experiments a temperature 
of —i5 0 to —16° C. (3.2 0 to 5 0 F.) was always fatal to trichinae and 
noted no exceptions such as were observed by the present writer. 
In experiments in which trichinous meat was exposed to temperatures 
of about o° F., but ranging as low as — io° in some instances, trichinae 
were rarely found to be alive. However, 100 per cent were found to be 
alive in one experiment (No. 67) in which meat had been exposed to a 
temperature of — 4 0 to o° for 5 days, but in 15 experiments in which 
the period of exposure to cold ranged from 6 to 23 days trichinae were 
found alive only in three instances and less than 1 per cent in each case 
(experiments 12, 68, and 70). 
Test animals were fed in all but 1 of the 23 experiments with tempera¬ 
tures of about o° F. Infection resulted in two instances. Four rats 
fed in experiment 67 (—4° to o°, for 5 days) became heavily infested, 
and one out of four in experiment 68 (—9° to o°, for 10 days) showed 
three trichinae in the diaphragm, the three other rats being negative. 
In the latter case, as in the former, live trichinae had been found by 
examination of the meat; less than 1 per cent, however, as compared 
with 100 per cent in the former, the results of the feeding tests thus as 
usual being quite consistent with the results of the examinations of 
artificially digested meat, though it was unusual for infection to result 
when the examination showed such a small percentage of live trichinae 
as in experiment 68. In experiment 86 (—2° to + 2 0 , for 15 days), 
in which no trichinae were found alive on examination of artificially 
digested meat, the result of the feeding test is considered to have been 
negative, although one of the five test rats, which died four days after 
feeding, was found to. have three trichina larvae in the intestine, two of 
which were dead, whereas the other one exhibited feeble movements. 
None of these three larvae, however, had undergone any development, 
and the four other test rats were negative, so that it seems quite proper 
to conclude that the viability of the trichinae had been destroyed in the 
meat in question. 
