LORD BROUGHAM'S APPENDIX. 477 



deprived of their latent heat, from the union of the bases 

 of inflammable air and of dephlogisticated air ; if this idea 

 had been accompanied in their minds by as much eleanu-ss 

 as in that of Lavoisier, they would eertainly have avoided the 

 uncertainty and obscurity which I have pointed out.* 



As far as relates to Watt, the following are the new facts 

 that we have succeeded in establishing. 



1. There is no proof that anybody had given, in a written 

 document, anterior to Watt, the present theory of the compo- 

 sition of water. 



2. Watt established this theory during the year 1783, in 



* At the foot of p. 333, of the Tr</*<ictint (for 1784), in a part of 

 his April letter, 17>:>, printed in italics, \\ att said: "Arc we not 

 thru authori/.cd to conclude that water is composed of dephlogist i 

 eatcd air and phlogiston deprived of part, of their latent or elemen- 

 tary heat: that dephlogisticated air. or pure air. i> composed of water 

 deprived Of its phlogiston and united to elementary heat and light ; 

 that heat and light are contained in it in a latent state, since they do 

 not affect either the thermometer or the eye? If light is only a modi- 

 fication of heat, or a peculiarity in its exi-tence, or a constituent part 

 of inflammable air, then pure or dephlogisticated air is composed of 



water deprived of its phlogiston, and united to some elementary 



heat." 



Is not this passage as clear, precise, and intelligible as Lavoisier's 



conclusions? (Note by Mr. }\',ttt,jim..) 



The obscurity complained of by Lord Brougham in the theoretical 

 conceptions of Watt and of Cavendish appears to me unfounded. In 

 1784 they knew how to prepare two permanent, and very dissimilar 

 ibises. Those two gases were by sonic distinguished as pure, air and 

 intlammable air: by others as dephlogistieated air and phlogiston ; 

 by others, finally, svs oxygen and hydrogen. By the combination of 

 dephlogisticated air and phlogiston, they generated water weighing 

 as much as the two gases. Thenceforward water was no longer a 

 simple body; it was composed of dephlogistieated air and phlogiston. 

 The. chemist who deduced this conclusion might have false ideas on 

 the internal nature of phlogiston without its casting any uncertainty 

 on the merit of his first discovery. Has it been even now maflui,iti- 

 cttUy iknwnstrnted that hydrogen (or phlogiston) is an elementary 

 body; that it is not, as Watt and Cavendish for a time supposed, the 

 combination of a radical with a little water V ( AWr hi/ M. Ar(i(/o.) 



