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LIX. On Chemical Combination ; and on the Amount of Heat 

 produced by the Combination of s'veral Metals ivith Oxygen. 

 By Thomas Woods, M.D. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen Parsonstown, Sept. 1852. 



THE two following papers were read at the Meeting of tlie 

 British Association at Belfast. I was not present ; but 

 reports of some remarks made by Dr. Andrews there, as well as 

 a paper in the Supplementary Number of this Journal for last 

 July by Mr. Joule, increase my confidence by saying that 

 one of the fundamental truths, the idea of which my theory sug- 

 gested to me, and which I had been at great pains to prove, had 

 been conjectured by the former, and had actually been proved 

 although not published by the latter. On account of these 

 remarks I think of course the more highly of the theory I pro- 

 pose : I have, however, no wish to take the merit either of the 

 ideas or work of others ; and lest I should unconsciously be 

 treading on beaten ground, I will briefly state what I consider 

 myself principally responsible for. 



1st. By right of prior publication the j^?-oo/ that decomposition 

 causes as much cold as the combination of the elements produced 

 heat. 



2nd. The idea that when two bodies are brought together at 

 insensible distances, as in solution, their particles may be regarded 

 as physically forming one body ; and the mixture of these pai'- 

 ticles therefore subject to the same laws as if it were a simple 

 body. 



3rd. That every substance being composed of a definite amount 

 of space as well as matter, the former as well as the latter must 

 influence and be taken into account in chemical combination. 



4th. That the amount of heat or relative volume in matter can 

 neither be increased or diminished, whatever one body loses or 

 gains being necessarily taken up or given off" by some other. 



And 5th. That therefore the supposition of attraction or I'e- 

 pulsion between the particles of matter is unnecessary. 



I believe I am also the first who endeavoured to obtain the 

 amount of heat by the oxidizement of the metals in the moist way. 

 I have the honour, &c., 



Thomas AVoods. 



On Chemical Combination. 



Dismissing all hypothetical ideas, and arguing from such phnc- 

 nomena only as can be demonstrated, I will endcavovir to divest 

 chemical action of any mysterious character or properties more 



