LAVOISIER. 271 



the other, but double the quantity operated upon.* 

 Such was the load of absurdity and contradiction under 

 which the favourite hypothesis of the day placed Priestley 

 entirely, Cavendish to a great degree, "Watt in some 

 sort; such was the weight of prejudice against which 

 Lavoisier had to contend; such was the maze of error 

 from which he boldly broke loose and extricated chemical 

 science. It is his glory that he first effected this emanci- 

 pation ; and it is no small proof of, his merit, that for 

 many years he remained almost alone among the philo- 

 sophers of his age, and even his own countrymen, how 

 prone soever to adopt French discoveries, in maintaining 

 opinions from which there is now, after the lapse of little 

 more than half a century, not a single dissenting voice 

 all over the scientific world. 



We are now to mark wherein he was led astray by 

 the love of theorising carrying him too far. He was not 

 content with shewing that combustion, contrary to the 

 phlogistic doctrine, proceeds from a union of the burning 

 body with other bodies; but he regarded the body 

 uniting as always the same, to wit, oxygen. Observing 

 the fact of many bodies burning in oxygen gas, and of 

 most other gases being unfit for supporting flame, he 

 generalized too much, and inferred that all combustion 

 consists in the union of that gas with the inflammable 

 body. Again : he regarded the heat and light given out 

 in the process as wholly proceeding from the gas, as 

 having kept the gas when latent in its aeriform state, 

 and as given out in a sensible form when the gas becomes 



* If common air (a) Phlog. = ox. gas, and com. air (a) + Phlog. 

 = azote; Ox. gas + azote = not a, as it ought to do, but 2 a. 



