During the past few years there has been a renewed interest in organic luetin in relation to the cutaneous reactions to its injection in syphilis. Several writers have given encouraging reports, the most optimistic of which have come from abroad. Noguchi,1in 1911, using a luetin prepared from an extract of killed ascites agar cultures of Spirochaeta pallida, found that the skin of untreated patients with primary and secondary syphilis reacted negatively, while 70 per cent of those who had received arsphenamine gave positive reactions. In cases of congenital and late syphilis, almost 100 per cent of the patients gave positive reactions. The luetin reaction often remained positive after the Wassermann reaction of the blood became negative. Cohen,2Ziegel,3Wolfsohn,4Pusey,5Brown6and others reported almost equally good results with Noguchi's luetin. The culture luetin continued to have many supporters until Clausz,7Sherrick,