314 Mr. Farailay oil the Formation of Ammonia, S^-c. 



Potash is not the only snbstance which produces this effect 

 with the metals and vegetable substances. Soda produces it ; 

 so also does lime, and baryta, — the latter not being so effec- 

 tive as the former, or producing the phenomena so generally. 

 The common metallic oxides, as those of manganese, copper, 

 tin, lead, &c., do not act in this manner. 



Water or its elements appear to be necessary to the expe- 

 riment. Potash or soda in the state of hydrates generally 

 contain the water necessary. Potash, dried as much as could 

 be by heat, produced little or no ammonia with zinc; but re- 

 dissolved in pure water and evaporated, more water being left 

 in it than before, it was found to produce it as usual. Pure 

 caustic lime, with very dry linen, produced scarcely a trace of 

 ammonia, whilst the same portion of linen with hydrate of 

 lime yielded it readily. 



The metals when with the potash appear to act by, or ac- 

 cording to. their power of absorbing oxygen. Potassium, 

 iron, zinc, tin, lead, and arsenic evolve much ammonia, whilst 

 spongy platina, silver, gold, &c., produce no effect of the 

 kind. A small portion of fine clean iron wire dropped into 

 potash melted at the bottom of a tube, caused the evolution 

 of some ammonia, but it soon ceased, and the wire blackened 

 upon its surface : the introduction of a second portion of clean 

 wii'e caused a second evolution of ammonia. Clean copper 

 wire, infused potash, caused a very slight evolution of ammo- 

 nia, and became tai'nished. 



The following, among other vegetable substances supposed 

 to contain no nitrogen, have been tried with potash in tubes 

 open to the air : iignine, prepared by boiling linen in weak 

 solution of potash, then in water, afterwards in weak acid, and 

 finally in water again ; oxalate of potassa, oxalate of lime, 

 tartrate of lead, acetate of lime, asphaltum, gave very striking 

 quantities to turmeric and litmus paper ; acetate of potash, 

 acetate of lead, tartrate of potash, benzoate of potash, oxalate 

 of lead, sugar, wax, olive-oil, naphthaline, produced ammo- 

 nia, but in smaller quantity; resin appeared to yield none, nor 

 when potash was heated in the vapour of alcohol or ether, or 

 in olefiant gas, could any ammonia be detected. 



It may be remarked, that much appeared to ilepend ujion 

 the quantity of potash used : sugar, for instance, which with 

 a little potash would with difficulty yield traces of ammonia, 

 does so very readily when the quantity of potash is doubled or 

 trebled ; and linen, which with potash gives ammonia very 

 readily, yields it the more readily^, and in greater quantity, 

 as the proportion of potash is increased. 



PROFESSOR 



