EFFECTS OF PORK-CURING PROCESSES ON TRICHINA. 9 
which the sausage was held after the salt was added to the meat 
varied from 22 to 28 days. Inasmuch as trichine survive in uncured 
meat much longer than 28 days, it may be concluded that the salting 
and drying of the sausage as practiced in these experiments were 
destructive to the trichine. The destruction of the parasites may 
not be ascribed entirely to the action of the salt, since drying enters 
as a complicating factor. It is quite evident, however, that the 
combination of salting and drying during periods ranging from 22 
to 28 days destroyed the vitality of the trichine and that infested 
sausage after such treatment became incapable of producing trichi- 
nosis, with the possible exception of the sausage in Experiment 22. 
The sausage in Experiment 22 (Table 2) was fed to four rats at 
the laboratory in Washington, and on post-mortem examination one 
of the rats was found very slightly infested with trichinz, the other 
three being free from parasites. Three rats fed at the laboratory of 
Establishment 2A, however, escaped infection. The sausage after 
stuffing was kept in the cooler for 6 days, then transferred to the 
drying room, where it was kept for 19 days. The first feeding of 
test animals at the Washington laboratory was given 2 days after 
the sausage was taken out of the drying room, so that a total period 
of 27 days had elapsed from the time the salt was added to the meat 
before the vitality of the trichine was tested at Washington, or 2 
days later than the Chicago test. It is by no means improbable, 
however, that the infection was extraneous, as a result of insufficient 
care on the part of the attendant in cleaning the cages and in feeding 
and watering the animals, thereby contaminating the food or water 
of the rats with material from other cages, some of which contained 
rats which had been fed trichinous meat. But even if the possibility 
of extraneous infection should be left out of consideration the infec- 
tion which was produced was so light as to be practically negligible. 
The post-mortem examination revealed but four encysted trichine 
in the entire diaphragm, which is known to be a favorite location of 
these parasites. Three other rats fed some of the same sausage for 
several days in succession at Washington and three similarly fed at 
Chicago escaped infection entirely. It may be noted in this con- 
nection that the sausage in question was made from pork trimmings 
of three well-infected hogs and that no beef trimmings were added 
to the pork. Thus the conditions were decidedly favorable to the 
production of heavy infections, even if only a small percentage of 
the larve survived the curing and drying processes. The pork 
trimmings used in a given lot of sausage that is prepared for the 
trade usually come from a large number of different hogs and are 
mixed with beef trimmings. This tends to dilute the trichina infec- 
tion, inasmuch as only a very small percentage of carcasses from 
185336°—20— Bull. 880—_2 
