in the Economising of Fuel. 183 



hydrogen of the moisture. The inferior quality of pig-iron 

 thus manufactured, owing perhaps to the abstraction of part of 

 the carbon by the moisture, and also, as stated by Mr Mushet, 

 to the inferior quantity of oxygen in a certain volume of the 

 air, induced an individual to try the introduction of steam into 

 the furnace, in the hope that, by supplying oxygen, the com- 

 bustion would be more complete. The attempt proved a fail- 

 ure, owing to the cooling effect immediately where the steam 

 was introduced, and the intense heat excjted higher in the fur- 

 nace, by which, in the course of time, the materials becoming 

 fluid, the furnace was actually closed up. The object in view 

 in using steam in this instance, is different from that which I 

 have proposed. I conceive that it will, if properly introduced, 

 increase the heat by the combustion of its hydroo-en, whereas, 

 in the case above mentioned, it was used under the impression 

 that it would do so, by yielding oxygen to the fuel ; and that 

 this is what was expected, is evident from Mr Mushet's own 

 words ; for he says, that the decomposition of the water, by 

 Jurnishing a superior quantity of oxygen, increases the effects 

 of combustion, &c. 



In the trial alluded to, Mr Mushet does not admit that there 

 is any increase in the total amount of heat in the furnace. There 

 is, he says, an increase in the immediate vicinity of the chemical 

 analysis, i. e. of the decomposition of the water ; yet, as the wa- 

 ter had abstracted heat from the inferior strata, in its ascent it 

 meets decomposition, and there yields up the abstracted heat 

 and also that contained in the oxygen of its decomposition, so that, 

 in fact, it merely conveys the heat from one part of the furnace 

 to the other, and there is, therefore, no actual increase in the 

 amount of heat throughout the furnace. In this I do not agree 

 with him. That there is really an increase in the actual amount 

 of heat when steam is properly introduced, is, I think, satisfac 

 torily established by the experiments I have mentioned. 



Though the use of steam in iron furnaces may prove inju- 

 rious, owing to the abstraction of part of the carbon, I consider 

 the trial recorded by Mr Murhet important, because it corro- 

 borates what I have before mentioned, that, instead of steam 

 being used with the view of supplying oxygen to the inflam- 

 mable matter, air, in other words oxygen, must be freely admit- 



