The problem of the treatment of late syphilis differs in essential particulars from that of early or of true asymptomatic (latent) syphilis. In early syphilis we are still, in spite of the disturbing revelations of Warthin,1 of Brown and Pearce,2 and of Eberson,3 striving for radical cure of the infection. In the late stages of the disease, the problem becomes one of symptomatic improvement and arrest. The early infection usually involves the unimpaired human body. In the late years of the infection the physiologic changes of advancing years are added to the disabilities produced by the action of the disease on vital structures. The characteristic reaction of the body to the syphilitic infection opposes another obstacle to treatment. The slowly progressive fibrosis walls off the organism from the carriers of remedial agents, the blood and lymph. By the induced obliterative endarteritis, the accessibility of foci to spirocheticides