During the last decade a number of investigators have employed various tests in the study of spinal fluids, principally qualitative chemical reactions for the presence of tryptophan groups, with a view toward the development of methods of differential diagnosis. The literature in regard to these tests is scant and deals more, perhaps, with the results on syphilitic rather than tuberculous spinal fluids.
Brugi1 applied the Furth and Nobel2 modification of the Voisinet test for tryptophan to forty-two spinal fluids from patients with the following diseases: tuberculous meningitis, proved by autopsy,twelve; meningism, two; syphilis, four; uremia, two; multiple sclerosis, one; hydrocephalus, five, and five fluids were from normal persons. Only the tuberculous fluids gave a positive reaction. Aiello3 reviewed the literature, principally Italian, and concluded that the reaction is positive in about 90 per cent of cases of tuberculous meningitis; that a negative reaction generally excludes the presence