344 BLACK. 



The last passage which has been cited from that 

 worK strikingly illustrates the low ebb at which 

 chemical science then was. It is certain that after 

 the discoveries of Black had opened vast and new 

 views of nature, both as regards the operations of 

 heat, the most powerful and universal of all agents, 

 and as regards the constitution of elastic fluids, the 

 most unknown of the four elements, no natural philo- 

 sopher would have had the hardihood to doubt if che- 

 mistry was an important branch of his science, and 

 no chemist would have performed the superfluous task 

 of vindicating its claim to the title. 



We have now gone through the whole of this in- 

 teresting subject, rather occupied in contemplating the 

 foundations of a new science than in tracing the exten- 

 sion of the boundaries which confine an old one. The 

 universal operation of heat, and the agency which it 

 exerts by its absorption and its evolution on the struc- 

 ture of all bodies, renders the discovery of its nature 

 and action in these respects, next to that of gravitation, 

 the most important step which has been made in the 

 progress of physical science. The new field opened to 

 philosophical inquiry by the discovery of the gaseous 

 bodies is only second to the former step in the import- 

 ance of its consequences. It is as objects of pure 

 science, the mere contemplation of scientific truth, 

 that we have been considering these great discoveries ; 

 yet they have amply contributed also to the advance- 

 ment of the arts. The illustrious improver of the steam 

 engine was too young to have joined in the experiments 

 on fixed air ; but in the course of those by which latent 

 heat was discovered, he had a constant and confidential 



