EPOCH OF THE THEORY OF OXYGEX. 279 



the essential part of the oxygen theory. Tt is a strong proof of 

 the steadiness and clearness with which the advocates of the new 

 system possessed their principles, that they immediately translated 

 this work, adding, at the end of each chapter, a refutation of the 

 phlogistic doctrines which it contained. Lavoisier, Berthollet, De 

 Morveau, Fourcroy, and Monge, were the authors of this curious 

 specimen of scientific polemics. It is also remarkable evidence of the 

 candor of Kirwan, that notwithstanding the prominent part he had 

 taken in the controversy, he allowed himself at last to be convinced. 

 After a struggle of ten years, he wrote 10 to Berthollet in 1796, "I 

 lay down my arms, and abandon the cause of phlogiston." Black 

 followed the same course. Priestley alone, of all the chemists of 

 great name, would never assent to the new doctrines, though his own 

 discoveries had contributed so much to their establishment. " He 

 saw," says Cuvier, 11 " without flinching, the most skilful defenders of 

 the ancient theory go over to the enemy in succession ; and when 

 Kirwan had, almost the last of all, abjured phlogiston, Priestley re- 

 mained alone on the field of battle, and threw out a new challenge, in 

 a memoir addressed to the principal French chemists." It happened, 

 curiously enough, that the challenge was accepted, and the arguments 

 Answered by M. Adet, who was at that time (1798,) the French am- 

 bassador to the United States, in which country Priestley's work was 

 published. Even in Germany, the birth-place and home of the phlo- 

 gistic theory, the struggle was not long protracted. There was, 

 indeed, a controversy, the older philosophers being, as usual, the 

 defenders of the established doctrines ; but in 1792, Klaproth repeated, 

 before the Academy of Berlin, all the fundamental 'experiments ; and 

 " the result was a full conviction on the part of Klaproth and the 

 Academy, that the Lavoisierian theory was the true one." 12 Upon 

 the whole, the introduction of the Lavoisierian theory in the scientific 

 world, when compared with the great revolution of opinion to which 

 it comes nearest in importance, the introduction of the Newtonian 

 theory, shows, by the rapidity and temper with which it took place, a 

 great improvement, both in the means of arriving at truth, and in the 

 spirit with which they were used. 



Some English writers 13 have expressed an opinion that there wa? 



10 Pref. to Fourcroy's Chemistry, xiv. " Cuvier, Eloge de Priestley, p. 208. 

 n Thomson, vol. ii. p. 136. 



11 Bramle, Hist. DISK, in Enc. Brit. p. 182. Limn, Chem. in Enc. Met. p. 5> 



