1847.] Memoranda on Explosive Cotton. 187 



less than that is attendant on the manufacture of gun powder. In 

 the preparation of gun cotton there are but two periods of risk — - 

 the first is while pressing the cake still full of acid. On one occasion 

 this caused an explosion, but of too trivial a nature to be worth descrip- 

 tion, and moreover the accident is one which cannot cause injury with 

 a press properly constructed. 



The last stage of drying unquestionably demands every precaution. 

 In my late experiments, a stray spark ignited at once ten pounds 

 of cotton which scorched more or less severely two men who, contrary to 

 orders, were quietly seated in the middle of the mass. Had this hap- 

 pened with the same proportionate quantity (40ibs.) of powder, there 

 can be no doubt what w r ould have been the result to the lives of the 

 men, and to the premises where the accident occurred. 



I repeat that during the other stages of the manufacture explosive 

 cotton is prepared with the most perfect safety. While it contains as 

 much moisture as can be perceived by the touch, it may be put into 

 a red hot crucible, or penetrated by a red hot poker with absolute 

 impunity. The hiss of steam and a few sparks are the only phenomena 

 observed. 



I have next to deal with the cost of the best kind of cotton, and 

 here it is that in a military point of view the chief objection arises to 

 its use. The annexed estimate shows in detail that to prepare gun 

 cotton from acids as sold in Calcutta at present, 1 pound of the best 

 kind costs about 10 Rs. But being fourfold the power of powder, this 

 may be considered as 2 Rs 8 as. for the corresponding quantity of 

 cotton. Now this is at least 8 times the price of ordnance powder, 

 range for range. 



But on the supposition that Government made their own acids, using 

 nitrate of soda, instead of saltpetre, economizing the washings, recon- 

 centrating the sulphuric acid, &c. the cost of the preparation would be 

 reduced so considerably, that allowing as above for superiority of power 

 the cost of cotton would be 2Rs. 9as 6pie per av. pound, being within 

 a fraction of double the price of powder, using quantities of equal 

 power* But this statement of course must be regarded as one resting 



* 10 as. 4 pie for range which would be procured from a pound of powder value 

 5 as. 



2 c 2 



