Nitro- Glycerine. 



99 



have laid before you, as I set out to do, two points : 1st. That 

 the spontaneous decomposition of nitro-glycerine is a result 

 of imperfect manufacture, leaving it partially impregnated 

 with nitrous fumes, or as I shall presently explain, some 

 impurity in the ingredients used. 



The second point is: That chemically pure tri-nitro- 

 glycerine may be transported, handled, or exposed to the 

 very roughest usage, when in a perfectly (not partially) 

 congealed state. The next lesson learnt with nitro-glyce - 

 rine, and which cost me §3,000 for the experiment, culmi- 

 nated on the 12th day of March, 1871. Ten days previously, 

 my superintendent of the works, accompanied by the 

 superintendent of blasting operations, came to me anxious 

 and troubled, saying : " We find on testing the last week's 

 manufacture (some two thousand pounds), that it will not 

 explode : here is a sample." Seeing their grave faces, I 

 replied : " I am heartily glad to hear this news : I have 

 been searching these five years past for a process to manu- 

 facture a nitro-glycerine, absolutely incapable of explosion, 

 and if you have blundered on it, accidentally, you have 

 made a point." Taking the sample they had brought with 

 them (it was a raw, cold, sleety day, in the latter part of 

 February), I found a lemon-tinted granular (like crystal- 

 lized honey), semi-solid matter. I dissolved it in sulphuric 

 acid cone, added nitric acid until separation ensued, and 

 poured the contents into abundance of water. Presently 

 the nitro-glycerine separated, and on collecting some on 

 blotting paper it exploded very readily. I next took 

 another specimen, dissolved it in wood naptha, threw the 

 solution into water, and the nitro-glycerine, which sepa- 

 rated, was very readily exploded. 



An examination of the materials used was then insti- 

 tuted, and the glycerine we had used was found to contain 

 some 4 per cent of a fatty !! acid. Now here we were with 

 two thousand pounds of nitro-gly cerise absolutely non-ex- 



