THE PURITY OF GLYCERIN. 25 



Powers, Weightman, Rosengarten Co., Philadelphia. 



Procter & Gamble Co., Cincinnati, Ohio. 



M. Werk Co., Cincinnati, Ohio. 



E. Schering, Berlin, Germany. 



Price's Patent Candle Co., London, England. 



DISCUSSION OF METHODS AND RESULTS. 



The samples were examined first according to the methods pre- 

 scribed in the Pharmacopoeia. A rigid examination was made for 

 arsenic in order to determine whether even traces of this substance 

 were left in the glycerin; special tests were made to note the action 

 on Fehling's solution, and a sample of Haines's solution was made 

 .up with each product. The physical appearance was good in every 

 instance. The samples were all neutral to litmus paper. The 

 specific gravities at 25 C. varied from 1.248 to 1.258, in most cases 

 being above 1.250, with an average of 1.254. In this respect they 

 were all above the standard requirement of 1.246 at 25 C. 



The pharmacopoeial test for sugar gave negative results, as would 

 be expected. Experiments were then conducted, noting the action 

 on Fehling's solution, using concentrated and diluted glycerin and 

 without previously heating with acid as in performing the sugar 

 test. Two samples which reduced Fehling's solution in the undi- 

 luted state gave no reduction on dilution; two reduced the solution 

 on diluting, but did not in the concentrated condition; three showed 

 no reduction either diluted or undiluted; while the remainder 

 reduced Fehling's solution under any condition. Several of the sam- 

 ples which reduced Fehling's solution in the undiluted condition 

 had reduced ammoniacal silver nitrate in the Hager test. Haines's 

 solution, when made according to directions given in works on 

 urinalysis 6 was reduced in every instance, thereby substantiating 

 the claims which had already been advanced in this connection. 



Most of the samples were well within the requirements as to the 

 color imparted by concentrated sulphuric acid, various shades of 

 yellow occurring. One sample was dark brown and fluorescent, 

 while another turned brown and gave off a strong fatty odor. In 

 fact, the odor varied more than the color, some samples having the 

 fatty odor just mentioned, while others had an unmistakably pleasant 

 aromatic smell; four had a characteristic hydrocarbon odor, and in 

 one instance the product was practically without color or odor, but 

 evolved a quantity of minute gas bubbles. When the samples were 

 treated with alcohol and sulphuric acid and warmed on the steam 

 bath ethereal odors were noted in all cases, the unpleasant butyric 

 ester predominating, although with two samples an agreeable fatty 



a Handbuch der Phann. Praxis, 4th ed., 1905, 1: 1221. 



fe Purdy, R. G., Practical urinalysis and urinary diagnosis. 1895, p. 103. 



c Mayer, J. L., The reducing action of glycerin, Merck's Report, 1905, 14: 165. 



21450 Bull. 15012 4 



