3^6 Itifammaikn^ isfc. nvith Oxygfffafcd Murlat of Bofajh, 



of the' fait prodDced a number of fucccflive detonations. The fulpburic acid produced 

 fhi'rr.e with fome explofions. 



'Mxp^'hmut XIII. ivhh Rofni. One part of this fubftance wiih two parts of the fait de- 

 tonated fucceffively when well rubbed together, llie fulphuric acid inflamed this mixture;^ 

 but the nitrous ac'wl did nor. 



Experiment XIV. loiih Gitm-Ai-nl'ic. The aetonations M-ere very flight. It was mixed 

 with twice its weight of the fait. The fulphuric acid fet fire to the mixture, but the ni* 

 trous acid would not. 



Experment XV. iv\th Priijfian Blue. No detonations whatever were produced hf 

 friftion, nor did the acids inflame a mixture of this fubftance with the fait*. 



E.rperiment XVI- nvith Indigo. Half a grain of fine Spanifli indigo rubbed with a graia 

 of the fait detonated fucceflivefy, like the mixture with roGn or gum. The fulphuric acid 

 inflamed this mixture, but the nitrous acid did not. 



Experlmtnt XVII. •with Elher. A few drops of ether on about two grains of the fait 

 rubbed to a very fine powder produced no detonation by friifiion. The fulphuric or ni- 

 trous acids poured fuddenly upon it produced flame. 



Experiment XVIII. luith Tron-fiVings. Thefe alone rubbed with the fait produced no de- 

 tonation by fimple friftion ; but two grains of the fait, one grain of iron-filings, and half 

 a grain of fulphur, being well rubbed together, about a quarter of a grain of this mixture ex- 

 ploded violently with friftion. The fulphuric acid added caufed a few fparks to appear \ 

 but the nitrous acid did not produce any. Varying the above proportions did not appear to 

 improve the detonating property of the mixture. 



Experiment XIX. ivith Aurum Mufivum. Equal parts of this fubftance and of the fait 

 detonated ftrongly with flame, on being rubbed together in an iron mortar : a very flight 

 fri£lion was necefl"ary. The fulphuric acid gave a fmall flame, but with the nitrous I could 

 not procure any. 



From the foregoing experiments I think we may venture to conclude, that the oxy- 

 genated muriat of potafli is equally harmlefs as common nitre ; except it be brought into an 

 intimate union with fomething that has a greater aflSnity with one of its conftituent parts, 

 than exifts between thofe parts when combined in the fait, and that fome combuftiible fub- 

 ftance be prefent : but its oxygen being fo eafily dlfengaged renders a little caution necef- 

 fary ; and as the fulphuric or nitrous acids feem fo readily to inflame many of the 

 mixtures, I would not advife any perfon to make more of them than is neceflary for imme- 

 diate experiment. This precaution may prevent any unpleafant circumftance from acci- 

 dental mixture with the acids, which appear to difengage a great part of the oxygen almoft 

 inftantaneoufly. 



I fhall not fay much about the theory of thefe detonations, none of the foregoing experi- 

 ments having been fo carefully conduced as to determine accurately what changes took 

 place ; yet I think we may attempt to explain fome of them in the following manner : With 

 phofphorus the oxygen feems to combine, and form phofphoreous acid gas, or phofphoric 

 acid ; with fulphur, the fulphureous acid gas, or fulphuric acid, according to the rapidity of 



* Chaptal (Elements of Chemiftry, vol. ii. page 377 J fiys, " Pruflian blue takes fire more eafily than ful- 

 ^ur, and eletopatts ftrongly with the oxygenated muriat of potafli. (Quaere, Did he not make uie of indigo 

 Iwr*?) 



the 



