532 Dr. R. Hare on the Explosiveness of Nitre, 



or of hydrogen in union with carbon, should, on ignition with 

 nitre, give rise to explosive reaction. Obviously, the conse- 

 quence of the displacement of nitric acid by water must be, 

 that the gaseous constituents of the acid, incapable of remain- 

 ing in combination without a base, would escape, either as 

 nitrogen, nitric oxide, or oxygen gas, or, carbon being pre- 

 sent, partially, as carbonic oxide, or carbonic acid. 



14. Gum, sugar, starch, and lignin, consist of carbon in 

 union with the elements of water, being virtually hydrates of 

 carbon. Oils, resins, or bitumens, consist of carbon and hy- 

 drogen, with but little oxygen. Of course either, when 

 heated with nitre, can supply water to the base of this salt, 

 with, if not without, assistance from its oxygen, which consti- 

 tutes nearly half of the matter in nitre. Such substances 

 may, therefore, under favourable circumstances, perform the 

 part performed by sulphur in gunpowder, which I conceive 

 to be that of seizing the potassium and liberating the acid, so 

 as to enable its oxygen to react freely with the carbon and the 

 resulting sulphide of potassium. Considerations analogous 

 to those advanced respecting the agency of the elements of 

 water in exploding with nitrates, will apply with respect to 

 those of carbonic acid ; since carbonated alkalies, no less than 

 the hydrated, being indecomposable per se by heat, carbon as 

 well as hydrogen must, by uniting with one portion of the 

 oxygen of the nitric acid and taking hold of the base, expel 

 all the nitrogen with the rest of the oxygen. 



15. Having submitted the preceding facts and considera- 

 tions, my explanation of the stupendous explosion which forms 

 the topic of this communication is as follows : — 



Of the enormous quantity of nitre which the store held, 

 more than 56,000 pounds were on the first floor, about 

 180,000 pounds on the second floor, and about 100,000 on 

 the third floor. The weight of combustible merchandise was 

 about 700,000 pounds. As it was alleged by some of the 

 witnesses examined that the iron window shutters of an upper 

 story became red-hot by the conflagration of an adjoining 

 house, it is probable that fire was communicated to some of 

 the gunny bags holding the nitre, or some other combustibles, 

 which, as stated in evidence, were piled against the shutters. 

 As soon, however, as a single bag became ignited, the nitre 



facts, I propose to show that there must have been a mechanical force in 

 operation sufficient to bring the matter into a state analogous to that 

 which enables fulminating combinations, or explosive mixtures of gas, to 

 detonate either from ignition, from exposure to an electric spark, or, in 

 some instances, from a blow or catalysis ; in other words, from some in- 

 fluence like that exercised by platina sponge. 



