13 



demonstrating that the study of the organs of an animal must he 

 subservient to the study of the tissues composing them, and while 

 Adanson, Duhamel de Monceau, Desfontaines, and especially 

 Jussieu were bringing to light many of the important facts con- 

 cerning the structure and physiology of the vegetable kingdom, 

 Rome de Lisle and Haiiy were as actively engaged in studying 

 the structure of minerals and applying the principles of geometry 

 to the elucidation of their forms. 



Turning, now, to Great Britain, we find that science, though not 

 so actively cultivated, during this period, as in France, was by no 

 means neglected. In 1753 was founded, at the cost of the govern- 

 ment, the British Museum, which for many years has been so largely 

 instrumental in promoting natural science in the United Kingdom. 

 Between the years 1759 and 1804, the science of therraotics was 

 greatly advanced by Black and Leslie, who, with much breadth of 

 mind and industry, not only demonstrated the laws of specific and 

 latent heat, but made possible the recognition of those remarkable 

 doctrines, the development of which has stamped the science of the 

 present century with its distinctive character. I allude to the inde- 

 structibility of force and the correlation of the forces as modes of 

 motion. At this time, many of the fundamental facts of chemistry 

 were discovered. Carbonic acid gas was isolated and studied in 

 1757 by Black. The discovery of ox}'gen was announced in 1774 

 by Priestlejr, together with a description of some of its important 

 properties. A year later he made known the fact that the air is 

 composed of oxygen and nitrogen; and in 1776 he made physi- 

 ology his debtor by proving that the change in color which the 

 blood undergoes in passing through the lungs is due to the ab- 

 sorption of oxygen an important and fundamental fact in the 

 chemistry of respiration. From 1799 to 1812, chemical science 

 was also promoted by Sir Humphry Davy, whose great achieve- 

 ment the decomposition of the fixed alkalies by galvanism 

 constituted a new era in this science. In 1808, just four years 

 before the founding of the Academy, Dalton gave another impetus 

 to chemical philosophy by announcing, as deductions from the 

 atomic theory, the well-known laws of definite combining propor- 

 tions laws which have done so much to perfect the analytical 

 and synthetical processes of the chemist. Another remarkable 

 discovery of this period the composition of water was made in 

 1783, by Watt and Cavendish, independently of each other. 



