On the Production of Muriates. 2.5 7 



acid vapourSj and caustic potash no ammonia. Tliev are, 

 on the contrary, inclined to believe that potash has some 

 share in the eflect ot" detonation ; since acids in which this 

 substance has been digested contain traces of salts having 

 potash as their base. When deprived of alkali this sub- 

 stance is more soluble tnwater, and crystallizes in elongated 

 plates of a vellovi' colour and bitter taste, having acid cha- 

 racters : these crystals, if moistened with potash, resume 

 their detonating property. The potash seems merely to 

 render this substance more fixed; to favour the accumula- 

 tion of caloric, and to determine, consequently, the combus- 

 tion of the elements which compose it; viz. of the carbon, 

 the hydrogen, and perhaps of the azote, by means of the 

 oxygen which it also contains. 



Indigo is not the only substance which furnishes this 

 detonating composition; the muscular fibre treated with 

 nitric acid presents the same phtenomena; and it is proba- 

 ble that bilk, wool, and other aninial and vegetable matters 

 containing azote will also furnish it. 



The labours of Messrs. Fourcroy and Vauquelin present 

 two very interesting facts. It follows, 1 . That the benzoic 

 ac'd may be formed from a multitude of different substances, 

 which we were formerly ignorant of: 2. That animal and 

 vegetable substances containing azote, if treated with the 

 nitric acid, which takes from them a portion of carbon, of 

 hydrogen, and of azote, give birth to a matter supersatu- 

 rated with oxyg-en, and possessing the property of detona- 

 tion. This substance, whicli the auibors. of the memoir 

 have examined with care, appears to them to be a super- 

 oxygenated hydro-carburet of azote. 



XLIX. Tliird Communication from Mr. W. Peex, of 

 Cambridge. On tlie Production of Muriates hy the 

 Galvanic and Electric Decomposition of Water. 



To Mr. TiUorh. 



SIR, 



1 FEEL no little satisfaction at the interest my experiments 

 have excited, and the favourable reception they have met 

 with from you. 



I have now the pleasure to inform yon, that since my 

 last letter, dated the 4th of June, (Phil. Mag. vol. x.xii. 

 p. 1.53.) having had some leisure time upon my hands, I 

 have dedicated as much of it as niv health would permit to 



Vol. 23. No. 91- Dec. 1605. K the 



