820 
Journal of Agricultural Research 
Vol. V, No. 18 
to — 21.25 0 C.) from January 6, 5 p. m., to January 7, 8 a. m.—i. e., for 
15 hours. Examined on a warm stage, the trichinae showed no movement. 
Some of the meat was fed to two rabbits on January 7, and on Febru¬ 
ary 7, a month later, the rabbits were killed. In one of them a few 
encysted trichinae were found. On January 16 he fed two rabbits with 
some trichinous meat which had been cut in fine pieces and exposed 
for 18 hours to a temperature of — n° to —12 0 R. (7.25 0 to 5 0 F.; 
—13.75 0 to —15 0 C.). On February 14 the rabbits were killed and 
carefully examined. No trichinae were found. 
Rupprecht (1864a) exposed trichinous meat during one night to an 
outdoor temperature of — i8°R. (—8.5° F.; —22.5 0 C.) and found that 
the vitality of the trichinae was not affected. 
Kuhn (1865b), according to Leuckart (1866a, p. 91), found that 
trichinous meat kept in an ice chamber for months was still infectious 
and that the trichinae had lost their vitality only after the meat had been 
kept for 2 months in the ice chamber, the temperature of which was 
not given. 
Gibier and Bouley (1882a) exposed some trichinous ham for 4 hours 
to temperatures of —27 0 C. (—16.6° F.) and —20° C. (—4° F.). In 
the first case the interior temperature reached — 20° C. (—4° F.) and in 
the second —15 0 C. (5 0 F.). All of the trichinae were found to be dead. 
They showed no movement when warmed, and they stained in a few 
minutes with anilin blue, methyl-anilin violet, and picrocarminate of 
ammonia. Some of the meat which had been frozen was fed during 
8 days to five birds, which when examined later showed no trichinae in 
the intestine; nor had any been found in the feces. Trichinae from 
portions of the ham which had not been frozen were active when warmed 
to 40° C. and remained transparent and colorless for several days in 
staining solutions. Five birds of the same kind and age as those to 
which the frozen meat had been fed were similarly fed with the ham 
which had not been frozen, and large numbers of trichinae were after¬ 
wards found in the feces and intestines. 
These experiments of Gibier and Bouley seemed to show pretty clearly 
the destructive effects of low temperatures upon trichinae, but later Gibier 
(1889a) came to the opinion that the death of the parasites was to be 
explained on the ground that they had already suffered a reduction in 
vitality from the action of salt, and, hence, readily succumbed to freezing. 
This opinion was based on the results of an experiment in which he 
exposed small fragments of fresh trichinous pork for 2 hours to a 
temperature of — 20° to — 25 0 C. (—4° to —13 0 F.). The parasites, 
when afterwards examined on a warm stage, were found to have lost 
none of their activity. 
From the foregoing it would appear that the usual statements found 
in articles relating to Trichinella spiralis as to the resistance of this 
parasite to low temperatures have their principal basis in Leuckart's 
