BODY TISSUES AND FLUIDS 473 



The sugar normally amounts to 0.07 to 0.09 per cent, in comparison 

 with figures of 0.09 to 0.11 per cent for the blood. Sugar appears to be 

 fairly readily admitted to the spinal fluid, since in diabetes comparatively 

 high figures may be found. Myers and Fine ( n ) observed a sugar content of 

 0.30 per cent in a case of diabetes showing a blood sugar of 0.44 per 

 cent. In meningitis the sugar content may be either very low or entirely 

 absent, negative findings more often being observed in epidemic and 

 pneumococcus meningitis than in tubercular meningitis. The estimation 

 of the sugar in meningitis may therefore be of considerable practical 

 value. 



The CO 2 combining power of spinal fluid averages 60 volumes per 

 cent, which is slightly lower than that of normal blood plasma. It like- 

 wise seems to vary within narrower limits. 



Of the mineral constituents of the spinal fluid the chlorids are by 

 far the most significant in point of quantity. Calculated as NaCl the 

 chlorids normally appear to average 0.7 per cent, more than half of the 

 total solid content. The content is considerably greater than that of the 

 blood plasma. It is ordinarily stated to be hypertonic to lymph, but 

 theoretically it would seem more likely that the high content of salt was 

 required to render this fluid isotonic with the blood. The chlorid content 

 of the spinal fluid is apparently increased in those conditions in which 

 an increase is found in the blood. 



.The phosphates of the spinal fluid, which normally amount to about 

 2.5 mg. per 100 c.c., calculated as P, are increased (8-10 mg.) in certain 

 mental disorders, notably paresis. In view of the importance attached 

 at the present time to the increase in the inorganic phosphates of the 

 blood in nephritis with acidosis, it may be of interest to note that Myers 

 in 1909 observed a P content of 19 mg. in the spinal fluid of a patient 

 dying from "arteriosclerosis." In view of the close relation of both 

 phosphoric acid and cholin in lecithin, note may be made regarding 

 cholin at this time. The presence of cholin in the spinal fluid of paretic 

 patients was first claimed by Mott and Halliburton, and confirmed by a 

 number of workers in this and other conditions involving nerve de- 

 generation. Later, however, the presence of cholin was disputed. 



The metallic elements, sodium, potassium, calcium and magnesium, 

 with the exception of the first named, apparently exist in the spinal fluid 

 in practically the same concentration as in the blood. Sodium appears 

 to be present in somewhat larger amounts as the high chlorin content 

 of the fluid would indicate. Some years ago Rosenheim reported that 

 potassium was present in relatively large amounts in cases of acute 

 degenerative insanity where cholin was present. In reinvestigating this 

 question Myers (6) found that the potassium content of the fluid in demen- 

 tia paralytica and several other conditions during life averaged 20 mg. per 

 100 c.c., but that after death the figures amounted to slightly more than 



