Lange considers—with much justification—that in spite of the fact that little is known of the nature of the colloidal gold reaction, it yields results of great clinical value and aids greatly in the differential diagnosis of certain diseases. The test was at first thought to be specific for paresis; later, Miller, Brush, Hammers and Felton confirmed Lange's work, but found that fluids from certain cases diagnosed as disseminated sclerosis gave curves of the paretic type. It can be stated that in spinal fluids which show a negative Wassermann reaction, with a slight increase of globulin, a negative cell count and a paretic type of precipitation of colloidal gold, in the absence of other signs of paresis in the central nervous system, it is well to consider the possibility of disseminated sclerosis. Greenfield and Carmichael1 stated that "so far as we know, disseminated sclerosis is the