150 On the Formation of Ammonia, $c. [1825, 



ammonia, but it soon ceased, and the wire blackened upon its 

 surface ; the introduction of a second portion of clean wire 

 caused a second evolution of ammonia. Clean copper wire, in 

 fused potash, caused a very slight evolution of ammonia, and 

 became tarnished. 



The following, among' other vegetable substances supposed 

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

 open to the air : Lignine, 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, tar- 

 trate 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 ammonia, 

 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 depend upon 

 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. 



The experiments with the substances which contain carbon, 

 assimilate, in consequence of the presence of that body, with 

 the one by Mr. Woodhouse. Whether the substances act 

 exactly as charcoal does, probably cannot be decided until the 

 correct nature of the action is ascertained; but there are 

 apparently some very evident differences. The ammonia in 

 the charcoal experiment does not exist until after the ignition, 

 nor before the addition of water; but in several experiments 

 of the nature of those described in this paper, the ammonia is 

 evolved before the substances acting or acted upon are charred. 

 Thus, if linen fibre, cut small, be mixed in the tube with hy- 

 drate of lime, and heated, ammonia is evolved before the heat 

 has risen so high as to render the linen more than slightly 

 brown; and oxalate of potash, in a tube with potash, when 

 heated, gives much ammonia before any blackening is produced. 

 Mr. Woodhouse's experiment may be very readily repeated. 



