Dr. A. Dupre on the Elimination of Alcohol. 



269 



eliminated daily would equal the daily consumption ; in other words, the 

 quantities which would be eliminated, if this theory were correct, might be 

 measured by ounces instead of by grains, and even the most ordinary pro- 

 cesses of analysis could not fail to yield considerable quantities of alcohol. 

 The argument loses nothing in force if it be contended that elimination 

 lasts longer than 10 days ; for, however long it may last, if the alcohol diet 

 is continued, a time must come when elimination and consumption would 

 be equal. Obviously, however, there is a tolerably narrow limit given to 

 the time during which elimination can be presumed to last ; for the alcohol, 

 if not eliminated, must accumulate in the body, and would speedily rise to 

 a proportion totally incompatible with life itself. The experiments re- 

 corded in the following pages were guided by the foregoing considera- 

 tions. 



Analytical processes employed. — Since, in the experiments of Messrs. 

 Perrin and Lallemand, the alcohol not recovered is accounted for as loss, 

 the author has thought it of importance to give the analytical processes 

 employed in greater detail than might otherwise be considered necessary. 

 It will thus be shown how much of the alcohol present can be recovered, 

 and how much may reasonably be accounted for as loss. Alcohol is elimi- 

 nated through four channels, — kidneys, lungs, skin, and bowel. 



Examination of the Urine. — The urine to he examined is rendered 

 slightly acid by dilute sulphuric acid ; some tannin is added to prevent 

 frothing, and about 1 of it is distilled over. This first distillate is now 

 made slightly alkaline by caustic potash or soda, and redistilled ; this 

 second distillate is once more acidified by sulphuric acid, and again distilled, 

 J being driven over each time. If these three distillations reduce the 

 amount of liquid to about 20 cuh. centims., it may at once be submitted to 

 oxidation. If, however, the amount of urine employed was so large that 

 this third distillate amounts to much more than 20 cub. centims., the re- 

 distillation must be repeated until the quantity is brought down to 20 cub. 

 centims. Less than three distillations should, however, in no case be 

 made. All distillations should, moreover, be conducted with an apparatus 

 in which both retort and receiver are connected air-tight with the con- 

 denser, the receiver being furnished with a safety-tube closed by a globule 

 of mercury. The final distillate is now put into a small assay flask, a 

 suitable amount of bichromate solution is added, the flask is closed by a well- 

 fitting caoutchouc-stopper tied down, and heated for one hour in a water- 

 bath. The flask is then taken out, cooled, opened, and the excess of 

 bichromate left is reduced by zinc. (The bichromate solution is made by 

 dissolving 147 grammes of potassium bichromate in water, adding 200 

 grammes of strong sulphuric acid, and making up the solution to 1400 

 cub. centims. Ten cub. centims. of this solution will oxidize nearly 0'2 

 gramme alcohol into acetic acid. After a little practice, it is easy to judge 

 by the colour of the liquid in the flask whether or no sufficient bichromate 

 had been added.) When all the bichromate is reduced, the green solution 



