2. Is the spinal fluid finding in this case consistent with multiple sclerosis? According to Nonne, about 19% of the cases of multiple sclerosis show globulin and pleocytosis in the spinal fluid. As a rule, the number of cells ranges between 10 and 20 per cmm. and the globulin is not present in large amounts. In this case, the amount of globulin, which was given as 2+, is only a moderate amount,—less than is usually found in cases of general paresis. There are not very many cases of multiple sclerosis in the literature in which a gold sol reaction has been performed, but in the majority of those tested, the reaction is reported as mild. However, cases of multiple sclerosis giving a typical paretic curve have been described by a number of observers, among whom may be mentioned Kaplan and Solomon. 3. How frequently is it necessary to make a differential diagnosis between multiple sclerosis and neurosyphilis? Before the days of the W. R. this differentiation was much more difficult than at present. But we, however, still have to face a not very rare difficulty in separating the two conditions. Syphilis is prone to cause small localized lesions in the nervous system. The changes in the patient’s condition, with improvements and regressions are equally characteristic of both diseases. How closely the symptomatology of neurosyphilis may simulate that of typical multiple sclerosis is shown in the next case (Lauder, 71). When the sclerotic area of multiple sclerosis occurs in appropriate parts of the cerebrum, symptoms of mental disturbances will occur. In its histological picture multiple sclerosis is at times highly suggestive of syphilis, even showing mononucleosis and meningitis. =Optic atrophy; nystagmus; spasticity; intention tremor. Diagnosis: ?= =Case 71.= James Lauder began to lose his eyesight at 32 years, and was shortly determined to be suffering from primary optic atrophy. In the course of a year, he had become completely blind. No mental symptoms had developed. =Physically=, Lauder was in very good condition. =Neurologically=, there was a complete optic atrophy with paralysis of the internal rectus muscle, marked nystagmus, and absent pupillary reactions. All the tendon reflexes were exceedingly lively, though the right arm reflexes were more lively than the left, and the left leg reflexes more lively than the right. There was an ankle clonus on both sides. The abdominal and cremasteric reflexes were lively. There was a slight intention tremor. There was, however, no ataxia and no speech defect.