32 BULLETIN 880, U. S. DEPARTMENT OF AGRICULTURE. 
An examination of the data in Tables 19 and 20 shows that with 
the exception of Experiment 285, Establishment 2A, and Experiment 
304, Establishment 3, the results of feeding experimental animals 
were negative. The pieces in Experiment 285, Establishment 2A, 
were fed to four rats in Washington, infecting all of them, and also 
infected the rats fed in Chicago. The test animals were killed one 
month after feeding and found to be heavily infected with trichine. 
The pieces in Experiment 304, Establishment 3, also infected the 
rats to which portions of the meat were fed in the Washington labo- 
ratory and the mice fed in the Chicago laboratories of Establishment 3 
(6 mice). The products in Experiment 285 were not dried subse- 
quent to smoking, but those in Experiment 304 were smoked for a 
long period (96 hours at a temperature of 68° to 83° F.) and were 
then dried for 8 days after smoking. 
Tt has been concluded that low-temperature smoking, even though 
it may be greatly prolonged, followed by drying, is not a reliable pro- 
phylactic measure against trichine in lockschinken. In experiments 
306 to 316, Establishment 3, high-temperature smoking for a period 
of 12 hours, similar to that employed in connection with fresh summer 
sausage was substituted for prolonged smoking at a low temperature. 
Although the results from this modification of method were very 
satisfactory in respect to the destruction of the trichine, further 
tests have been discontinued because it was found that the high- 
temperature smoking rendered the products unsatisfactory from a 
commercial standpoint. 
In view of the results of our experimental work the Bureau of 
Animal Industry does not recognize any curing method as adequate 
for the destruction of trichine in lockschinken, and this product may 
be prepared in official establishments only from pork that has been - 
refrigerated at a temperature of not higher than 5° F. for a period of | 
not less than 20 days in accordance with the results obtained in 
experiments on refrigeration recorded in a former paper (Ransom, 
1916). 
THE INFLUENCE OF SALT ON THE RESISTANCE OF TRICHINA LARVA TO HEAT. 
The experiments described below were performed in the 1aboratory 
of the Zoological Division in order to supplement the practical tests 
at the meat-packing establishments in Chicago, the aim being to 
secure data concerning the effects of preliminary curing on the resist- 
ance of trichine to heat. In connection with the discussion of the 
experiments on fresh summer sausage it was indicated that made- 
quate preliminary curing may vitiate the effects of subsequent 
smoking. The experiments described and tabulated below demon- 
strate this point. 
