Aug. 15. I9I5, Effects of Heat on Trichince 209 



Examination of 213 larvae on a warm stage showed 179 inactive and 34 

 active, most of them very lively. Another lot was heated from 30° to 5 1 .9° 

 in 10 minutes. Ninety-nine were examined, and of these 93 were inactive 

 and 6 active. Another lot was heated from 30° to 53° in 4 minutes. 

 One hundred and eighteen were examined, and of these 72 were inactive 

 and 46 active, sluggish. Another lot was heated from 22° to 53° in 12 

 minutes. One hundred and forty-seven were examined, and of these 

 109 were inactive and 38 active, sluggish. As a control upon the re- 

 sults of this experiment 158 unheated larvae from the same source as those 

 subjected to heat were examined on a warm stage. Of these 22 were 

 inactive and 136 active. 



Experiment 4 (November 17, 1914). — Decapsuled larvae, isolated by 

 artificial digestion from the meat of a trichinous hog, were heated in a 

 beaker of water over a hot water bath for a period of 10 minutes, during 

 which time the temperature gradually increased from 23° to 53.4° C. 

 The beaker was then cooled. Seventeen of the larvae were examined on 

 a warm stage and one was observed to move slightly. Fifteen minutes 

 later the lar\^ae remaining in the beaker were reheated to a temperature of 

 53.6° C, seven minutes being required to raise the temperature to this 

 point from 38°. Twenty-four larvae were examined after this reheating ; one 

 exhibited definite movements on a warm stage. The others were more 

 or less tightly coiled and presumably still alive. Thirteen minutes later 

 the larvae remaining in the beaker were heated a third time, the tem- 

 perature being raised rapidly (in 3 minutes) from 43° to 55°. Thirty- 

 nine larvae were examined; all were motionless and failed to react to heat, 

 evidently dead. 



Experiment 5 (November 17, 1914). — Decapsuled larvae from the same 

 source as those used in Experiment 4 were heated in the same manner 

 from 1 6° to 54° C, 7^2 minutes being required for raising the temperature. 

 Twenty-three lar\^ae were examined after heating and all were found to 

 remain inactive on a warm stage. The remainder of the larvae in the 

 beaker were left on the laboratory table until the following day when 42 

 of them were examined on a warm stage heated to 45°. Most of these 

 were inactive but more or less tightly coiled. Thirty-five others were 

 placed on a warm stage heated to 61 °. Six of these exhibited convulsive 

 movements before they succumbed to the heat, the others showing no 

 response to stimulation. 



Experiment 6 (November 17, 191 4). — Decapsuled trichinae, isolated 

 by artificial digestion from a mixture of meat from six trichinous hogs, 

 were heated in a beaker of water over a hot water bath to a temperature of 

 53.4° C. Some of them showed signs of life when examined on a warm stage. 

 The beaker was reheated to 55°. Fifty larva were then examined on a 

 warm stage and all were found to be dead. 

 122501°— 19 3 



