Jan. 31,1916 
Effects of Refrigeration on Trichinella spiralis 
821 
single experiment, to which may be added, as supplementary support, 
Fiedler’s first experiment, Rupprecht’s experiment, and Gibier’s experi¬ 
ment, a total of four experiments. Kiihn’s experiment perhaps has been 
considered as affording additional supporting evidence. The results of 
Fiedler’s second experiment do not offset the results of his other experi¬ 
ment, nor those of Leuckart’s and Gibier’s experiments, as the failure 
to get an infestation in the two rabbits which were fed meat exposed for 
18 hours to a temperature of 7.25 0 to 5 0 F. might have been brought 
about by something else than low temperature. Likewise, the results of 
Gibier and Bouley, when compared with those of Leuckart, Fiedler, and 
Gibier, tend to show only that trichinae are sometimes killed when 
exposed for a short time to temperatures below zero. The later explana¬ 
tion by Gibier (1889) that the trichinae used in these experiments had 
lost so much vitality on account of previous salting of the meat that they 
succumbed, whereas they would not have done so if the meat had been 
fresh, has been accepted by those authors who have mentioned Gibier 
and Bouley’s work. It should be noted, however, that in the experiment 
upon which Gibier (1889) based his explanation of the results of the 
earlier experiments by himself and Bouley the meat was exposed for 
only 2 hours as compared with 4 hours in the earlier experiments. 
So far as appears in the available literature, after the later experiments 
conducted by Gibier (1889), no further work on the effects of cold upon 
trichinae was done until the investigations undertaken by the present 
writer, 25 years later, the first of which were recorded briefly in an article 
(Ransom, 1914) already mentioned. 
A few additional data gathered in these investigations were given in a 
later paper (Ransom, 1915). 
Recently Schmidt, Ponomarer, and Savelier (1915) have published a 
preliminary report of some investigations of the effects of cold upon 
trichinae in which they state that a long series of experiments has led to 
the following results: 
1. A temperature of o° C. (32 0 F.) has no influence upon the vitality of 
encysted trichinae, even though it acts during a period of 11 days. 
2. A temperature of —6° C. (21.2 0 F.) is easily withstood by trichinae 
during a period of 10 days, but they revive slowly. 
3. A temperature of — 9 0 C. (15.8° F.) is sometimes fatal, but not 
always. The results are not always the same; they are uncertain. 
4. A temperature of —15 to — 16° C. (5 0 to 3.2 0 F.) is always fatal; 
the trichinae never revive. 
Winn (1915) exposed some trichinous meat out of doors away from the 
sun in February, 1914, for 16 days, at an average mean temperature of 
—18.8° C. (—2° F.) with a minimum of — 25 0 C. (— 13 0 F.) and a maxi¬ 
mum of —12.2 0 C. (io° F.). Nine guinea pigs were fed upon this meat, 
and none became infested. 
