228 Intelligence and Miscellaneous Articles. 



have existed respecting the competency of fused nitre to explode with 

 water, or with aqueous, hydrogenous, and carbonaceous combustibles. 

 This subject was treated of in reference to a series of detonations ter- 

 minating in an explosion of tremendous force, by which, in July 1845, 

 the intensely ignited contents of a store in Broad Street, New York, 

 were thrown over an extensive district, involving the destruction of 

 about 200 houses and property estimated at two millions of dollars. 

 As far as the oaths of highly competent witnesses could avail, no 

 gunpowder was present, so that tlie result could only be attributed 

 to the reaction between an enormous quantity of nitre and combus- 

 tible merchandize with which the store was promiscuously occupied. 

 In all there were 300,000 lbs. of nitre in parcels of 180 lbs. (each 

 secured by two bags, an additional bag having been put over that 

 originally employed). About 30,000 lbs. was situated upon the first 

 floor, 180,000 on the second floor, and 80,000 on the third floor. 



Of the merchandize, the aggregate was more than double the 

 weight of the nitre. 



It was however the general opinion of those best acquainted with 

 the subject, that when ignited with combustibles, nitre produces only 

 that species of combustion which is called deflagration by chemists, 

 without being capable of the more violent and instantaneous reaction 

 designated by the word explosion. This impression was strengthened 

 by the failure of every effort (made by several eminent chemists em- 

 ployed by the Corporation of New York) to explode nitre by ignition 

 with combustibles. 



Nevertheless, agreeably to Hays, of Massachusetts, an explosion 

 was effected in his laboratory, by bringing water into contact with 

 about 100 lbs. of incandescent nitre ; also the accidental falling of a 

 jet of melted nitre on some water in the laboratory of the University 

 of Pennsylvania had been productive of a similar result. 



The explosion of a vessel laden with nitre, which, while lying in 

 Boston harbour, was burnt to the water's edge, and of others simi- 

 larly laden and burnt, could only be explained by supposing that 

 nitre, when sufficiently heated, will explode with water on due con- 

 tact. Consistently, it might be inferred that this salt (well-known 

 to be a compound of nitric acid and oxide of potassium or potash) 

 would explode with any substance capable of yielding either or both 

 of the elements of water or hydrogen. The presence of the latter 

 would be equivalent to water, since it would, with the oxygen of the 

 acid, form water. 



In a letter addressed to the distinguished chemist above-mentioned, 

 in July 1845, Dr. Hare had adverted to the explosion which succeeds 

 the combustion of potassium upon water, as arising from the combi- 

 nation of one portion of the water with the resulting incandescent 

 globule of oxide, while the heat of this globule uniting with another 

 portion of the liquid, converts it into high steam. Moreover, it was 

 suggested that in this instance chemical affinity between the water 

 and the oxide, in causing the water and heated globule to coalesce, 

 is equivalent in efl&cacy to the momentum of the hammer when a bar 

 of iron, at a welding heat, is forced into contact with some moisture 

 situated upon an anvil. 



