276 PROGRESS OF SCIENCE. 



of whom may justly intimate that without him the success 

 in this or that branch would have been problematical ; 

 and this is true, for the XlXth century has made the 

 INTERACTION of the sciences a fact so commanding that all the 

 mathematical, astronomical, mechanical, physical, chemical 

 sciences tend to become one, so intimately and indissolubly 

 are they connected with one another. Look at the labour 

 accomplished by chemistry. Do not the metallurgist, the 

 astronomer, the geologist, the biologist, the physicist, the 

 photographer rely upon the data or the analyses furnished 

 by the chemist in order to carry out their own work ? It 

 might almost be said that chemistry has become the key 

 of the secret palace of science. But CHEMISTRY is even 

 more intrinsically : it has devised new means of analysis, 

 through which it has revealed to us the components of 

 the universe. That, by itself, would be sufficient to make 

 the XlXth century equal to the age of Newton. 8. In 

 the natural sciences, our time has been no less thorough 

 than in other departments ; the earth is now known, thanks 

 to geology, which has raised the veil which concealed the 

 past ages, and shown us the growth of the crust, the 

 revolutions it has undergone, the life it has supported, 

 the age it has lived ; so that the XlXth century has 

 given us the knowledge of our EARTH, and has completed 

 or at least immensely extended the knowledge of the 

 HEAVENS. 9. Another feature, as engrossing as the others 

 if indeed it be not more so, is that afforded by the rapid 

 advance and grand revelations made in all the branches 

 of biology, including anthropology. Here again the XlXth 

 century inquirer found the secret of nature, life, describing its 

 innumerable delineations, explaining its countless varieties, 

 ascending to its primitive forms. And not this only, but 

 his brother, the physiologist, the good magician, has dis- 

 covered the means of abolishing pain, and of preventing 

 disease. 10. Finally, in all the branches just alluded to, 

 laws have been found, and of all these laws, one which 

 could never have been elucidated in earlier ages the grand 

 LAW OF EVOLUTION, which embraces a sheaf of others. 



In all branches the XlXth century has touched the 



