CH. XXIII. DEVELOPMENT OF SCIENCE. 189 



CHAPTER XXIII. 



SCIENCE OF THE EIGHTEENTH CENTURY. 



Great spread of Science in the Eighteenth Century — Advance of the 

 Sciences relating to Living Beings— Foundation of Leyden Univer- 

 sity in 1574— Boerhaave, Professor of Medicine at Leyden, 1701 — 

 Foundation of Organic Chemistry by Boerhaave— Influence of Boer- 

 haave upon the study of Medicine — Belief of the Alchemists in 

 * Vital Fluids' — Boerhaave's Experiments on the Juices of Plants— 

 Dr. Hales' Experiments on Plants — Boerhaave's Analyses of Milk, 

 Blood, &c. — Great popularity of his Chemical Lectures. 



We have now arrived at the beginning of the eighteenth 

 century, only 175 years before our own day, when the dif- 

 ferent sciences which we have been tracing in their rise, Hke 

 Httle rills on the mountain sides, were beginning to swell 

 out into mighty streams, widening and spreading so rapidly 

 that it is in vain we strain our eyes to try and watch 

 them all. The time had now come when any man who 

 wished to be a discoverer was obliged to devote his whole 

 life to one branch of science, following it out in all its in- 

 tricate windings. And so we find that about this time each 

 science begins to have a complete history of its own, with 

 its own eminent men, and its peculiar language growing 

 more and more technical so as scarcely to be understood by 

 ordinary readers. 



For this reason most general histories of Science stop at 

 this point and refer their readers to special works on the 

 different sciences. I do not, however, propose to do this ; 



