In a communication entitled "Studies of the Therapeutic Effect of Fever in Experimental Rabbit Syphilis,"1 we stated that rabbits could be protected from syphilis after intratesticular inoculation of spirochetes, if they received eleven consecutive daily hot baths under certain conditions. The average rise of temperature induced in the rabbits was 4 F.
We also asserted that we had found that if a spirochetic suspension were heated on a water bath in a test tube for one hour at 41 C. (106 F.) it was incapable, as a rule, of producing syphilis, although under the darkfield microscope the spirochetes were numerous and motile.
It is proper for us to say that a repetition of this experiment did not terminate in quite the same manner. In January, 1927, we inoculated eighteen rabbits with syphilis. Six were inoculated with a spirochetic suspension which had been heated on a water bath for one