518 Rev. W.V.Harcourt on Lord Brougham's statements 



into sulphuric acid : he negatived by conclusive experiments 

 these three suppositions of condensation : at this crisis of his 

 inquiry Warltire burnt inflammable gas and common air in a 

 vessel which he imagined to be close, and finding a very sen- 

 sible loss of weight, concluded, with Scheele, that ponderable 

 matter had passed through the vessel's pores in the form of 

 heat : at the same time he repeated an observation, made also 

 by others, that in the combustion water was deposited from 

 the air, in which he supposed it to have been contained', to 

 the mind of Cavendish, deeply meditating what might be the 

 form of matter into which the lost airs could have been con- 

 densed^ this inaccurate experiment immediately suggested the 

 light for which he was watching. Such is his own descrip- 

 tion of the manner of the discovery; and the course of expe- 

 riments recorded in his note-book leave no shadow of a doubt 

 that he has described it with truth. 



In the progress of these experiments, that is to say, in his 

 fourth experiment of exploding the gases, in an apparatus like 

 Warltire's but really close, on the 5th day of July 1781, 

 Cavendish arrived at the exact volume of hydrogen which de- 

 stroyed in combustion the whole of its own elasticity, with the 

 whole elasticity of the exact volume of oxygen found to exist 

 in the common air with which he exploded it: in the same 

 experiment he ascertained that the vessel, which was of such 

 capacity as to hold 24,000 grains of water, had lost scarcely 

 one-fifth of a grain in weight : he then varied his apparatus 

 in such a manner as to collect a sufficient quantity of the 

 liquid formed in these experiments, for chemical examination, 

 and before the end of the month demonstrated it to be pure 

 water. 



And now point out to me, if you can, in the whole range 

 of experimental science three facts the ascertainment of which 

 was more obviously and indubitably conclusive of the point 

 in question ? Is there any alternative left for scepticism ? 

 The total weight undiminished — three volumes of elastic 

 matter gone — in its place pure water — could any man draw 

 any conclusion from such experiments but one? could any- 

 thing but one foregone conclusion have led a man to institute 

 such a course of experiment? Does the man who has instituted, 

 and made, such experiments, want any one to come to him 

 two years afterwards with an idle doctrine, or hypothesis, as 

 you call it, about the connection of water with some undefined 

 kind of phlogiston, by way of explaining to him his own in- 

 vestigation ? What is the use of a doctrine, or a hypothesis 

 after an inductive demonstration, even if the hypothesis had 

 had any real substance or distinctness of meaning ? Are we to 



