ELEMENTARY COMPOSITION OF NITROGLYCERINE. 



91 



No. of 



Nitroglycerine 



Percentage 



Corrected for loss 



Percentage 



Experiment, 



Employed. 



Nitrogen found. 



of NH 3 . 



Calculated. 



I. 



A 



17-77 



18-15 



\ 



II. 



A 



1747 



17-85 



III. 



A 



17-76 



18-14 





IV. 



B 



17-76 



18-14 





V. 



C 



17-76 



18-14 



> 18-50 



VI. 



F 



17-41 



17-79 





VII. 



J 



17-81 



18-19 





VIII. 



N 



17-73 



18-11 





IX. 



Nobel's 



17-77 



1815 



/ 



These figures agree closely not only with each other, but with those obtained 

 by us by Dumas's method. Our analyses already given prove nitroglycerine 

 to be glyceryl tri-nitrate : these analyses render it highly probable that it is 

 invariable in composition, and that therefore the statements of some previous 

 investigators, particularly those of Hess, are erroneous. If nitroglycerine at 

 any time does contain the lower nitrates of glyceryl, it is probably owing to the 

 nitroglycerine having been very imperfectly washed in the process of its 

 manufacture. Nitroglycerine is only very slightly soluble in water ; glycerine 

 is freely soluble in water ; and, reasoning from chemical analogies, it is highly 

 probable that the intermediate nitrates possess intermediate degrees of 

 solubility, which will readily permit of their removal by an ordinarily complete 

 washing of the nitroglycerine with water, but may allow only of their partial 

 removal if a limited quantity of water is used. According, however, to the 

 published description of the various commercial processes for the preparation 

 of nitroglycerine, the washing appears to be sufficiently thorough to remove 

 the lower nitrates ; for the amount of washing necessary to remove traces of 

 the free acid used in the manufacture of nitroglycerine is certainly quite 

 sufficient to dissolve out the lower nitrates. 



VOL. XXXII. PART I. 



