50-1 



Mr. G. S. Johnson. 



The total volume operated on (Table I) was thus 34,640 c.c. The 

 mean specific gravity was 1*020, and the mean reduction of picric acid 

 (expressed in terms of glucose) was equivalent to 0*67 grain of glncose 

 per fluid ounce. 



The spherical mercury salt obtained from the above urine, after 

 being washed with cold water and dried in vacuo over sulphuric acid, 

 weighed 198 grams. This is at the rate of 5*7 grams of the spherical 

 compound to each litre of urine. 



The mean specific gravity at 16° C. of the above samples (Table II) 

 of normal human urine is 1*022, and the mean reduction of picric 

 acid is equivalent to that which would be effected by a solution con- 

 taining 86 grain of glucose per fluid ounce. 



The washed and dried spherical mercury salt from the above 

 40,625 cc. of normal urine weighed 293*13 grams, which is equivalent 

 to 7*19 grams per 1 litre of urine. 



It is apparent from the above tables that the weight of mercary 

 salt obtained from an equal volume of urine is proportional to the 

 amount of reduction effected by the secretion, and that both have a 

 tendency to increase with the specific gravity of the latter. 



The following observations made upon my own urine daring the 

 past winter, illustrate some interesting points in connexion with the 

 precipitation of normal urine by mercuric chloride : — 



My weight at the time of the experiment was 70*08 kilos. I was in 

 good health, in active work both mental and bodily, and consuming an 

 ordinary mixed diet. All the samples had the normal acid reaction to 

 litmus, and were free from albumen and sugar. 



The total urine of each twenty-four hours, having been measured, 

 was mixed with a cold saturated solution of sodic acetate, and then 

 precipitated with one-fourth of its volume of cold saturated solution 

 of mercuric chloride. Both first and second precipitates were collected 

 on filters previously counterpoised, washed with cold water, dried in 

 vacuo over H 2 S0 4 , and weighed. 



The total volume of urine during the six days amounted to 

 8930 c.c. 



Average per 24 hours 1488 c.c. 



Maximum in ,, ........ 1790 ,, 



Minimum in 1230 „ 



