156 PA\ ASITOLOGY. 
groups of muscles; the pain lasts only during the 
migration of the embryos; after encystment there is no 
pain. Hogs:—The intestinal form causes diarrhoea; 
the migration of the embryos pruritus, rubbing, 
scratching, stiffness of gait, difficulty in swallowing 
and mastication, difficult and painful respiration. 
The disease is usually fatal in man; it is not liable to 
be fatal in the hog or rat. 
Vitality.— Vermifuges and vermicides have little 
effect upon them. Degeneration usually destroys 
the larvae in the cysts in from twelve to eighteen 
months, although cases are on record where their 
vitality has lasted much longer. They will live one 
hundred days in decaying meat. Fourteen degrees 
below zero, Cent., will kill them. 
Complete salting kills those that are superficial in 
a short time, but those in the deeper parts live for a 
long time. Sausagein pickle 15 days destroys them. 
Sausage in hot smoke kills them in 24 hours, cold 
smoke 3 days. 
To determine if Trichina are alive two methods 
can be used. First, feed a small bird the trichinous 
flesh and kill the bird 8 to 10 hours after; if the 
trichini are dead they will be digested with the cyst; 
if they are alive they will be coiled or moving. 
Second, ifa small particle of macerated meat contain- 
ing the cysts be placed on a platinum plate and heat- 
ed to a temperature of 100 to 105 degrees Fahrenheit, 
then noted under the microscope, movement will be 
seen if they are alive. Thorough cooking destroys 
them. To destroy the trichina in a ham it should 
be cooked thirty-five minutes for each two pounds 
of weight. 
