CAVENDISH AND LAVOISIER. 431 
year; but the letter remained in the archives of the 
Society.* It is inserted in the seventy-fourth volume of 
the Philosophical Transactions, under its true date of 
the 26th of April, 1783. It is found there inserted in a 
letter from Watt to De Luc, dated 26th of November, 
1783, distinguished by inverted commas, applied by the 
Secretary of the Royal Society. 
I do not ask for indulgence on this profusion of details, 
it will be perceived that a minute comparison of dates 
could alone bring the whole truth to light ; and that the 
subject is one of those discoveries that do most honour to 
the human mind, 
Among the pretenders to this fruitful discovery, we 
are now going to see arise the two greatest chemists 
boasted of by France and England. Everybody must 
have already named to themselves Lavoisier and Caven- 
dish. . 
The date of the public reading of the memoir in which 
Lavoisier detailed his experiments, in which he devel- 
oped his views on the production of water by the com- 
bustion of oxygen and hydrogen, is posterior by two 
months to Watt’s letter (already analyzed) being depos- 
ited in the archives of the Royal Society of London. 
The celebrated memoir by Cavendish, entitled Hxperi- 
ments on Air, is more recent still; it was read the 15th 
of January, 1784. It might excite reasonable surprise 
* To this diffident and philosophical document we refer the reader; 
in it Watt states that he feels great reluctance to lay his thoughts 
“before the public in their present indigested state, and without 
having been able to bring them to the test of such experiments as 
would confirm or refute them.”’ M. Arago, in rendering portions of 
the paper, resorts to the exact chemical language of the present day; 
whence he uses hydrogéne for inflammable air and phlogiston, and 
oxygene for dephlogisticated air.— Translator. 
