472 



VICTOR C. MYERS 



COMPOSITION OF NORMAL SPINAL FLUID 



advantage of the changed reaction of the fluid in the last mentioned 

 conditions and the rate of change of alkalinity on standing, Tashiro and 

 Levinson have devised a very valuable method of differentiating tubercular 

 from epidemic meningitis. If to 1 c.c. of spinal fluid there is added 1 c.c. 

 of 3 per cent sulphosalicylic acid, and to another 1 c.c. of fluid a like 

 amount of 1 per cent mercuric chlorid, then in tubercular meningitis the 

 protein which settles down on standing 24 hrs. is more voluminous in 

 the mercury tube, whereas in epidemic meningitis it is more voluminous 

 in the sulphosalicylic acid tube. 



The nonprotein nitrogen of spinal fluid averages only about 70 per 

 cent of the figures obtained in blood, but this statement does not apply to 

 its chief component, urea. It is now well known that the various mem- 

 branes of the body are very permeable to urea, resulting in an even 

 distribution of this waste product throughout the tissues of the body, as 

 shown by Marshall and Davis. Cullen and Ellis have strikingly pointed 

 this out in the case of spinal fluid. Myers and Fine(n) likewise have found 

 this to be true in nephritis with marked nitrogen retention. In their 

 series of fifteen cases the spinal fluid urea averaged 88 per cent of that 

 of the blood. The concentration of creatinin averaged 46 per cent of 

 that found in the blood in the same series, indicating that it did not 

 diffuse as readily as the urea. In one case with the high blood creatinin 

 of 14.5 mg., the spinal fluid content was 4.8, while in a similar case the 

 figures were 11.0 and 4.2 mg. respectively. Uric acid does not readily 

 pass into the spinal fluid, if one is to judge from observations on the same 

 cases, since the amount present averaged only about 5 per cent of that 

 found in the blood. In a few exceptional cases the figures for the spina] 

 fluid reached only about 1 mg., and this despite the fact that the blood 

 content was about 10 mg. 



