A STUDY OF THE SPIROCHÆTICIDAL ACTION OF THE SERUM OF PATIENTS TREATED WITH SALVARSAN

1. The serum of rabbits treated intravenously with neosalvarsan, and of syphilitic patients treated intravenously with salvarsan or neosalvarsan, has a definite spirochæticidal action upon Spirochœta duttoni. 2. Although this spirochæticidal action is exerted in vitro, it can be demonstrated only after the treated spirochætæ are injected into susceptible animals. 3. A curative action of the serum of neosalvarsan-treated rabbits is exercised on mice infected with Spirochœta duttoni. 4. The spirochæticidal action of the serum of salvarsan-treated rabbits and patients is markedly increased by heating at 56° C. for thirty minutes. 5. The increased spirochæticidal action produced by heating is due in part to the destruction of some inhibitory substance contained in normal serum and in part to a direct effect of the heat upon the serum and salvarsan mixture. 6. Cerebrospinal fluid does not contain the inhibitory substance present in normal unheated serum.