THE JOURNAL OF PHARMACOLOGY. 7 



1. Solution of chlorinated soda of the U. S. Pharmacopoeia, 1840- 1870, 

 inclusive. 



2. An extemporaneous solution of chlorinated soda, prepared according 

 to directions accompanying the apparatus. 



3. Solution of chlorinated lime. 



4. Solution of sodium hypobromite applied by the improved process of 

 Dr. Charles Rice. 



No description of the apparatus, nor any directions for using, will be 

 given here, as this information is exhaustively furnished with each ap- 

 paratus. Each apparatus is also accompanied by full directions for the 

 preparation of reagents employed. By carefully following directions, 

 acceptable results may be obtained. 



Fowler's Differential Density Method. 

 This method devised by Dr. G. B. Fowler, of New York, answers fairly 

 well for approximate results and is easy of application. It is based on the 

 difference in gravity of urine before and after the decomposition of its 

 urea. The regent employed is lyabarraque's solution. Each degree of 

 density lost corresponds to 0.77^, or about 3^4 grains for each fluid ounce. 

 The method is executed as follows : To one volume of urine, add 7 vol- 

 umes of Eabarraque's solution. Decomposition of urea begins to take place 

 at once, and after a few hours all the nitrogen has escaped. The specific 

 gravity of the mixture is now carefully taken, preferably by the pyknom- 

 eter. The specific gravity of the original sample of urine and of the 

 Labarraque's solution must also be taken in the same careful manner. 

 The density should be carried out to the third decimal. In order to re- 

 duce the density of the decomposed and diluted urine, to its normal undi- 

 luted condition, multiply the specific gravity of Eabarraque's solution by 

 7, add the specific gravity of the original sample of urine, and divide the 

 product by 8. From the specific gravity before decomposition, subtract 

 that obtained after decomposition, and multiply the difference by 3^^, giv- 

 ing as result the number of grains per fluid ounce, or by 0.77 giving the 

 per cent. The method cannot be recommended where accuracy is required, 

 but will answer where only approximate results are desired. 



To be continued. 



