INFLAMMABLE GAS» 243 



containing the smaller, the second, the greater proportion of 

 that constituent. 



If an)' confidence is to be put in the experiments imme- New gasroxy- 



diately to be detailed, the o;as which forms the subject of this caibnreted hy- 



' , . . diogen. 



paper constitutes a fourth species of inflammable air fiom vege- 

 tables, to which i-he name of oxycarhurtted hydrogen may be 

 given, a, name already applied by BerthoIIet to carbonic oxide, 

 but to wh.ch the gas f.om peat is much better entitled. If I 

 shall be so unfonunate as to fall into error, I hope the diffi- 

 culty of the subject will, in some measure, constitute an 

 apology. 



Hitherto the gas obtained during the distillation of peat, has Gas from peat, 

 been examined only, as far as I know, by Mr. William Henry, jr'j)^"™ ^ 

 of Manchester. But as the properties of his gas differ essen- 

 tially from those of mine, it is very clear that the gases must 

 -have been of a different nature. Indeed, I have ascertained, 

 hy experiment, that different kinds of peat yield different kinds 

 of gas, though I have not been so fortunate as to form any gas 

 possessed of the properties which he describes; doubtless, be- 

 cause the peat which he employed was very different ffom any 

 which 1 cou!d procure. 



The peat used in all ray experiments was the kind com- The gas ob- 

 TTionly sold in Edinburgh: its quality was very indifferent ; for ^^luhor ^w ''^^ 

 it wassof[, brown-coloured, and very spongy, and loose in its different. Cha- 

 iexture. Its <;pecific gravity was only 0.600. When kept at Y'^^^"^^^*^ °^ 

 the tenperature of 300°, it lost 1 -4th of its weight. Between 

 400° and 500°, it smoked, and was charred, emitting the usual 

 vapour of burning peat. When heated to. redness, in close 

 vessels, it left a very brlae charcoal, amounting to l-4th of its 

 weight. When burnt in the open air, it left a quantity of yel- 

 lowish grey ashes, containing iron, amounting to 1- 100th 

 part of the peat. Good peat is much denser, not so easily 

 decomposed, and approaches more closely to coal. 



With this peat cut into small fragments, I sometimes filled Experiments 

 an unglazed earthen retort, sometimes a cast-iron bottle, and fjonson^th^ein- 

 then exposed these vessels respectively to a degree of heat riammablc gJis 

 which was purposely varied in the different processes. Some- peat. 



times the peat was kept for a considerable time at a tempera- 

 ture not exceeding bQQ^ ; and when all gas had ceased to come 

 over, it was raised to a red heat. Sometimes it was placed at 

 once in a strong red heat, and sometimes it was never allowed 

 X 2 to 



