306 Royal Institution, 



upon the peculiar genius and talents of the discoverer : he espe- 

 cially praised the mathematical precision and statical ac;c\iracy 

 which glitter in his dissertations. He should not endeavour to 

 draw a parallel lietween the philosophical character of Mr, Ca- 

 vendish, and that of his fellow labourers in science, for he ad- 

 mitted not of comparison ; " he was himself alone." 



Toward-s the conclusion of his lectnre the Professor summed 

 up the additions which the labours of Black, Priestley, Seheele, 

 and Caven(Ush, had made to the stock of chemical knowledge ; 

 the elements of the ancieuLs had vanislied before them ; air and 

 water had each been decomjjounded, and had yielded new ele- 

 ments ; their properties had been investigated, and the inquiry 

 had thrown an entire new light upon the science: such were the 

 favourable auspices under which Lavoisier and his associates 

 entered the field of chemical philosophy. 



Mr. Braiule in his eighth lecture resumed his History of 

 Chemical Philosophy with the discoveries of Lavoisier and the 

 views of the French School. ^Vith Lavoisier, as with his prede- 

 cessors in the field of theoretical chemistry, the phsenomena of 

 combustion were a leading object of attention, and Black's 

 theory of latent heat was assumed as the groundwork of his new 

 views. Oxygen was considered as the only supporter of com- 

 bustion ; in its gasequs state it was regarded as a compound of 

 a peculiar basis, combined with light and heat ; during the pro- 

 cess of combustion the ponderable basis luiited to the burning 

 body, while the light and heat were developed in the form of 

 flame. Oxygen, as its name imports, was also looked upon as a 

 necessary constituent of all acids — it was described as the uni- 

 versal acidifying principle. 



Having illustrated these views by experiment, and enlarged 

 upon their applications by the French chemists, the Professor 

 jjroceeded to notice the weak and faulty parts of the theory which 

 had been raised upon them. In regard to the evolution of heat 

 and light depending upon the transition of oxygen from the 

 gaseous to the solid form, Mr. Branfie remarked, that it often 

 took place during the change of that principle from its solid or 

 liquid, to its aeriform state ; as in the combustion of gun- 

 powder, and of oil of turpentine and nitric acid ; that the re- 

 sult of combustion in oxygen gas was often itself gaseous, and 

 that numerous substances burned with great energy and splen- 

 dour, independent of the presence of aeriform matter : this was 

 shown by several experiments ; the most striking was the vivid 

 combustion of phosphorus, on being brought into contact with 

 iodine in an exhausted receiver. As to the necessary presence 

 of oxygen in acidsj the Professor remarked, that although many 



acids 



