Jan. 31.1916 
Effects of Refrigeration on Trichinella spiralis 
853 
Trichinae thus released from their capsules may remain alive and retain 
their normal activity for 10 days or more when kept in a 0.6 per cent 
sodium-chlorid solution at a temperature of about 20° C., and have been 
found alive and moderately active at the end of 26 days. They may 
likewise be kept alive for two weeks or more in tap water at a temperature 
of about 20 0 C. Trichinae have been kept alive and very active for 11 
days in a 2 per cent sodium-chlorid solution at a temperature of about 
20 0 C. Trichinae in tap water warmed to a temperature of 38° C. become 
inactive within a few hours, but may be kept in a 0.6 per cent sodium- 
chlorid solution at this temperature for a similar length of time without 
apparent injury. 
In the practical application of refrigeration as a means of destroying 
the vitality of trichinae, meat should be refrigerated at a temperature not 
higher than 5 0 F. for not less than 20 days, a period which allows a 
probable margin of safety of nearly 10 days. The employment of higher 
temperatures of refrigeration as a means of destroying the vitality of 
trichinae is not justified in the light of our present knowledge because of 
the uncertainty of the effects of such temperatures. Whether tempera¬ 
tures higher than 5 0 F. may be safely employed by lengthening the period 
of refrigeration remains to be determined. 
LITERATURE CITED 
Bachmann, Fritz. 
1914. Die Ursache des Erfrierens und der Schutz der Pflanzen gegen den Kaltetod 
<Naturwissensch., Berl., v. 2 (36), 4. Sept., p. 845-849. 
FiedeEr, A. 
1864. Weitere Mittheilungen fiber Trichinen <Arch. d. Heilk., Leipz., v. 5, 
p. 466-472; 511-520. 
Gibier, Paul. 
1889a. Sur la vitality des trichines <Compt. rend. Acad. d. sc., Par., v. 109 (14), 
30 sept., p. 533 - 534 - 
-; and Boueey, Henri-Marie. 
1882a. Effets du froid sur la vitality des trichines <Compt. rend. Soc. de biol., 
Par., v. 34, 7. s., v. 4, p. 511-512. 
KtfHN, Julius. 
1865b. Untersuchungen iiber die Trichinenkrankheit der Schweine <Mitth. d. 
landwirthsch. Inst. d. Univ. Halle, Berl., p. 1-84, 1 pi., fig. i-vi. 
Leuckart, K. G. F. R. 
1863a. Die menschlichen Parasiten und die von ihnen herriihrenden Krank- 
heiten. Ein Hand- und Lehrbuch fur Naturforscher und Aerzte. 
v. 1, viii+766 p., 268 fig. 8°. Leipzig & Heidelberg. 
1866a. Untersuchungen fiber Trichina spiralis. Zugleich ein Beitrag zur Kennt- 
niss der Wurmkfankheiten. 2. stark vermehrte und umgearbeitete 
Aufl. iv p., 1 1 ., 120 p., 1 1 ., 7 fig., 2 pi. 4 0 . Leipzig and Heidelberg. 
Ransom, B. H. 
1914. The effect of cold upon the larvae of Trichinella spiralis ^Science, N. Y., 
n. s. (996), v. 39, Jan. 30, p. 181-183. 
1915. Trichinosis. [Read Feb. 17] <Rep. U. S. Live Stock San. Ass., Chicago 
(18. Ann. Meet., Feb. 16-18), p. 147-165. 
