47 2 ^(10 Experiments on Chemical DiUnctloii, 



The nitrates of barytes, of ftrontian, and of magnefia, by deficcation, detonateJ with 

 nearly the fame force as the nitrate of potafh. 



I had ftlll remaining five grains of the oxygenated muriate of ammoniac, of which I took, 

 the half, with about four grains of phofphorus. I (lightly cruflied thefe two fubftances, 

 with the intention of mixing them together, wlien a detonation fo terrible was heard that 

 the whole houfc was alarmed. The phofphorus was for the moll part thrown upon mv 

 hat, which it burned for a long tine before I perceived it. The violence of the blow caufed 

 the hammer to fly out of my hands. I very diftindly felt it raifed by the expanfion of 

 the gafes. The other half of the oxygenated muriate of ammoniac was placed alone upcr.i 

 the bottom of an inverted iron moytar, and flruck rather brifiily with the cold hammer. The 

 hrft blow caufed it to detonate, but no light was difengaged. I regretted that no more of 

 this fait remained to make the experiment with fulphur and charcoal. 



I alfo (truck the nitrate of ammoiiiac alone. The fourth blow caufed it to fulminate, t 

 fay it fulminated, becaufe the detonation was accompanied with a difengagement of light. 



I obtained an effeft equally confiderable from the white nitrate of mercury and ammo - 

 niac. I think that all the nitro-ammoniacal triple falts will detonate more or lefs (Irongiy 

 with phofphorus. 



I was defirous of trying the folid oxygenated muriatic acid ; for which purpofe I caufed 

 this acid to cryftalHze by artificial cold. A few cryftals of this acid were put together, 

 with a fmall piece of phofphorus, upon an iron mortar placed in a cooling mixture. When 

 thefe were llruck with a hamm'er, a dull detonation was heard at the fixth or feventh blow. 

 The fufed acid was projedled to a diflance. 



I repeated a great number of thefe experiments with pyrophorl and the phofphori called 

 artificial carefully prepared; and in almoft every cafe I obtained a detonation. I fliall de- . 

 fcribe my experiments on thefe lingular inflammable preparations in a feparate article. 



Whenever I flruck the before-mentioned mixtures with a heated hammer, I always ob- 

 tained a weaker detonation, at the fame time that the inflammation was (Ironger ; and when 

 the hammer was too hot, no detonation or noife was produced. This obfervation I had al- 

 ready made with the oxygenated muriate of potafh ; and it appears to me to explain the 

 phenomena of detonation. The blow with the cold apparatus, by ftrongly comprefling 

 the matter, and perhaps exciting fome heat, produces a partial combuflion of the phofpho- 

 rus, and confequently engages only part of the oxygen of which the other portion aflTumes 

 the elaftlc (late, and produces the noife of the detonation. At a very elevated temperature 

 the eflfcfts are not altogether the fame. All the oxygen is at once employed to burn the 

 combuftible, whence the inflammation is the ftrongelt, and no detonation takes place. In 

 fa£t it is obfervable, that the more fudden and fonorous the noife, the lefs is the develope- 

 ment of fire ; and the contrary. To this principle alfo is referable the obferration made by 

 Brugnatelli, which I have found to be true, that the oxygenating body muft in fome in- 

 ftances po(rcfs the form of a lump to obtain the efFe£t ; becaufe it applies too extenfively 

 to the combuftible matter when powdered. 



Thefe experiments fucceed much better by ,fri£lIon than by a blow, and the eiFe£l$ 

 take place more readily upon a rough than a fmooth body. I ufually place the two fub- 

 ftances on the bottom of an inverted marble mortar, which is left rough from the faw. 



' Upon 



