THE THERMAL INACTIVATION TIME AT 41.5 degrees C. OF THREE STRAINS OF HERPES SIMPLEX VIRUS.

1. The thermal inactivation time at 41.5 degrees C. of the H. F. and Frank strains of herpes simplex virus, under the conditions described, was 80 hours. 2. A strain of herpes virus recently recovered from a patient treated with a physically induced fever had a thermal inactivation time of 50 hours at 41.5 degrees C. 3. The neurotropic factor of the H. F. and Frank strains of virus was more resistant to a temperature of 41.5 degrees C. than the dermotropic factor. There was little difference in the thermostability of these two factors of the Go strain.