438 



JAMES WATT. 



lei ray, infinitely diluted with the solar light that falls on 

 the first surface, issues from the second surface, diverging 

 and with a sensible breadth, it is because the glass sepa 

 rates that which, in the white pencil, was by its nature 

 unequally refrangible.&quot; These words are nothing but a 

 literal translation of the known experiment of the pris 

 matic solar spectrum. This translation, however, had 

 escaped an Aristotle, a Descartes, a Robert Hooke. 



Without departing from the subject, let us come to 

 some arguments which will lead in a still more direct line 

 to the point. The theory conceived by Watt of the com 

 position of water reaches London. If it had been accord 

 ing to the ideas of those times, as simple, as self-evident 

 as it appears to us now, the counsel of the Royal Society 

 would not have failed to adopt it : but its strangeness 

 made them doubt the correctness of Priestley s experi 

 ments. They went so far as to laugh at it, said De Luc, 

 as at the explanation of the golden tooth. 



A theory, the conception of which did not present any 

 difficulty, would certainly have been despised by Caven 

 dish. But recollect with what eagerness, under the in 

 spiration of that man of genius, Blagden claimed the 

 priority of it against Lavoisier. 



Priestley, to whom a great part of the honour of Watt s 

 discovery belonged, Priestley, whose affectionate sen 

 timents for the celebrated engineer cannot be doubted, 

 wrote to him, under date of the 29th April, 1783, 

 &quot; Look with surprise and indignation at the drawing of 

 an apparatus, by the aid of which I have irrevocably 

 undermined your beautifid hypothesis.&quot; 



In conclusion, an hypothesis at which they laughed in 

 the Royal Society ; which made Cavendish emerge from 

 his habitual reserve ; which Priestley, laying all self-love 



