The inactivation of the virus of infectious myxomatosis by heat

The virus of infectious myxomatosis of rabbits, in common with other viruses, is inactivated by brief exposure to temperatures in excess of 5000., or prolonged exposure to more moderate temperatures. Berry and Dedrick (1936) in pre-paring a vaccine of inactivated virus heated suspensions to 600C. for 30 minutes. Hurst (1937) in similar experiments heated the virus to 6000. for 40-50 minutes. Fiske and Kessel (1931-2) prepared two vaccines: one heated to 60°C. for 30 minutes, and one exposed to 4500. for 24 hours; the virus in each was completely inactivated. The object of all of these investigators was, however, simply to ensure that no active virus remained in the heated suspension. Hobbs, (1928) in an effort to determine the "thermal death point", heated virus to temperature