346 Dr. Thomson, Mr. Hill, and Dr. Halliburton. 



The Rate of Flow. 



One portion, collected by the patient herself in the course of an hour, 

 measured 4 c.c. Another portion, collected under the supervision of 

 one of us (StC. T.) in ten minutes, measured 3*9 c.c. 



If the first portion is taken as a measure of the rate of secretion, the 

 amount formed in the day will be 96 c.c. Taking, however, the second 

 observation as being more accurate, the amount formed in the twenty- 

 four hours will be over half a litre (561*6 c.c.). It is possible that this 

 estimate is too high, as doubtless the patient, being under the observa- 

 tion of a physician, would be somewhat excited, and the consequent 

 alteration of the circulation would, as we shall immediately see, cause 

 the flow to become more abundant. 



Comparison of the Morning and Evening Fluid. 



Cavazzani,* from experiments on dogs, found that the cerebro-spinal 

 fluid collected in the morning was more alkaline than in the evening, 

 and contained more solid residue. He considers that this is related to 

 the activity of the nervous system, and that it confirms Obersteiner's 

 theory of sleep. He obtained corresponding results in the case of a 

 man with traumatic fistula of the frontal bone. 



We considered it worth while to repeat this observation. 



The qualitative examination of the fluid collected first thing on 

 several mornings gave the same results as that of specimens collected 

 the last thing in the evening. Both were distinctly alkaline, but no 

 estimation of the relative alkalinity was made. The following table 

 gives in percentages the results of the quantitative analyses : 



Morning fluid. Evening fluid. 



Water 99'004 99'027 



Solids 0-996 0'973 



Organic solids 0' 1 1 8 0- 1 00 



Inorganic solids ... 0'S7S 0-873 



The evening fluid is thus slightly poorer in both classes of consti- 

 tuents than that of the morning ; the difference is chiefly due to an 

 alteration in the organic solids. This is just what we should expect, 

 as the decreased capillary pressure during sleep would lessen the rate 

 of exudation of water. Without committing ourselves to any theory 

 on nervous activity or sleep, we may say that our experiments confirm 

 those of Cavazzani. 



* "Sul Liquido Cerebro-spinale," 'La Eiforma Medica,' Anno VIII, 1892, 

 vol. 2, p. 591. 



