2l8 



Scientific Proceedings (108). 



average fall of pressure in a large series of experiments was 258 mm. 

 normal saline. The changes were roughly proportionate to the 

 concentration of the salt and the size of the dose. Two per cent, 

 sodium chloride solution in large doses or a saturated solution in 

 doses as small as 5 c.c. gave corresponding though less marked 

 effects. Non-absorbable salts gave similar reductions though slower 

 in occurrence and less in extent. Dextrose solution caused still 

 less striking results though identical in nature. 



The converse results seen after the ingestion of hypotonic 

 solutions (water) were not great in extent nor well sustained. 

 A previous dose of a hypertonic solution rendered more extensive 

 the rise of pressure in these cases. 



The changes observed were independent of blood pressure and 

 were not attended by significant alterations of pulse or respiration. 



These effects on cerebrospinal fluid pressure and brain volume 

 were investigated in patients. An excellent opportunity for this 

 was afforded by patients with brain tumor and cerebral herniae 

 subsequent to decompression operations. In these patients there 

 was a lowering of tension when hypertonic salines were given by 

 mouth. Occasionally very striking results could be obtained 

 in which case the tense convex protrusion became a soft concave 

 area over the decompression site. 



121 (1581) 



Some results with a new technique in vitamine measurement. 



By Walter H. Eddy and Helen C. Stevenson. 



[From the Department of Physiological Chemistry, Teachers College, 

 Columbia University and the Department of Pathology, New 

 York Hospital, N. Y. City.] 



By means of a technique described in detail in the March, 

 1920 number of the Proceedings certain results have been at- 

 tained that seem to indicate the specifity of the test for the "B" 

 vitamine. These results are briefly as follows: 



(a) Application of the test to three specimens of Funk's 

 antineuritic vitamine prepared in 1912 and '13 showed that the 



