Examination of the Cerebro-spinal Fluid as an Aid to Diagnosis in Certain Cases of Insanity, with Special Reference to the Protein Reaction described by Ross and Jones
The main points of practical interest in the examination of the cerebro-spinal fluid are the protein reactions and the cell-count. Both are of great value for the early diagnosis of general paralysis, tabes, or cerebral syphilis.

The simplicity of the Ross and Jones test brings it within the reach of any qualified man, and it would appear to be the most delicate of all the protein reactions.

So far as I know this series is the largest in which the reaction has been tested. Ross and Jones only tested 27, and Amsden 36 cases.

At the present time the other characters noted, the acidity or alkalinity and the presence of copper-reducing substance, are mainly of academic interest. It is probable, however, that the degree of acidity to phenolphthaleine may coincide with the development of lactic acid in the fluid during life, and this with the disappearance or lessening of the copper reducing substance; so that inasmuch as lactic acid is rapidly formed in dying nervous tissue, we may have here the means of establishing a test as to the extent of the organic nervous changes in any given case.

Writings on the subject of the spinal fluid are now so numerous that some apology is almost needed for adding to their number, especially when, as in my case, nothing new is recorded. Still, I felt it was worth while further testing the trustworthiness of such a simple reaction as that described by Ross and Jones, by its application to a larger number of cases than has hitherto been done, and from my results it appears to come successfully out of the ordeal.