9G ANNUAL OF SCIENTIFIC DISCOVERY. 



One volume of nitre-glycerine produces : 



Carbonic acid gas, 469 vols. 



Water at 100 C., 554 vols. 



Oxygon, 39 vols. 



Nitrogen, 236 vols. 



One volume becomes 1,298 vols. 



These volumes are given at the temperature degree C. ; at 

 the temperature of explosion, they will be about 5 times greater, 

 or about 10,607 times the original volume of the explosive, or 

 about 10 times as large a production of mixed gases for the nitro- 

 glycerine as for the gunpowder which produces mixed gases in 

 largest amount. 



Still 13 times is claimed by the advocates of nitro-glycerine. If 

 this is so, the discrepancy between the temperature of the explo- 

 sion must be greater than here assumed. 



UTHOFRACTEUR. 



Analysis shows that " Lithofracteur," as well as dynamite, 

 consists of a mixture of a silicious base with nitro-glycerine. The 

 proportion of glycerine appears to be that which the base can 

 take up without becoming sensibly moist. Dresdner Gewerbeve- 

 reins-Zeitung. 



In the " Centralblatt," of Oct. 15, can be found a discussion of 

 the merits of the above. Its exact composition appears to be 



Nitro-glycerine, 52 



Silicious base, : 30 



Coal, 12 



Saltpetre, 4 



Sulphur, , 2 



DUALIN. 



Professor Mowbray, who superintends the manufacture of nitro- 

 glycerine at North Adams, for the Hoosac Tunnel, writes to the 

 " Springfield Republican " in regard to the explosion at Worces- 

 ter, Mass. He finds that dualin consists of 60 per cent, mono- 

 nitro-glycerine and 40 per cent, of sawdust. 



The mono-nitro-glycerineis exceedingly unsafe to manufacture, 

 to use, or to transport; it is not nearly as destructive as the tri- 

 nitro-glycerine and yet is far more dangerous to handle. There 

 are 3 different nitre-glycerines. Of these 2 are the most dan- 

 gerous and not as powerful as the third, which is not dangerous 

 but very difficult to explode, and when exploded is 33 per cent, 

 more powerful in its effects than either of the 2 others. 



Trials were made with dualin at the Hoosac Tunnel, and were 

 complete failures. Only about 50 per cent, of results as com- 

 pared with the nitre-glycerine in use at the tunnel were obtained, 



