Proteins of Cerebrospinal Fluids. 155 



recent results by Harriet Chick and others have shown that this 

 is not a sharp method for separating euglobulin from the other 

 globulins. Its most characteristic property is its insolubility at 

 its isolectric point, but owing to its low concentration (.001 to 

 .020 per cent.) in spinal fluids the estimation in this way has never 

 been attempted heretofore. 



From the diluted spinal fluid the euglobulin is precipitated by 

 adding a trace of acid to help free it from its alkaline salt, and 

 diluting. The diluting not only tends to hydrolyze any unneutral- 

 ized salt of euglobulin but decreases any solvent action due to 

 electrolytes. 



To 2 c.c. of diluted spinal fluid were added 0.50 c.c. .01 N 

 acetic acid and 10.00 c.c. of distilled water, and after waiting a 

 few minutes the suspension was matched with a known casein 

 solution (see total-protein estimation). 



It may have occasionally happened that the amount of .oiiV 

 acetic acid was either too much or too little, in which case a 

 slight error resulted, but all the figures given here were obtained 

 in that way, using 0.50 c.c. .01 N acetic acid. 



The Wassermann reactions were performed as described by 

 Field in the Archives for Internal Medicine, 13, 790 (1914) and the 

 Jour. Amer. Med. Assoc., 62, 1620 (19 14). 



The chemical and Wassermann tests were made independently, 

 without duplicates, in separate institutions, and the figures were 

 not compared until the end of the series. 



The results with total protein estimations show, assuming that 

 figures above .050 per cent, indicated pathological increase, that 

 34 cases out of 51 agreed with positive Wassermann reactions, 

 while 48 out of 54 agreed with negative Wassermann reactions. 



Similarly, the figures of the total globulin estimation showed, 

 assuming .020 per cent, or less as normal, that 24 cases out of 31 

 agreed with positive Wassermann reaction, while 44 out of 54 

 cases agreed with negative Wassermann reactions. 



The euglobulin content seemed to show remarkably close 

 agreement to the Wassermann test: those above .004 per cent, 

 agreed with positive Wassermann test in 14 out of 16 cases, and 

 those below .004 per cent, agreed with a negative Wassermann 

 reaction in 33 out of 35 cases. Of these 4 discrepancies we have 

 good reasons to doubt the figures obtained in at least 2 of them. 



