CONTENTS. 



CHAPTER XX. 

 SCIENCE OF THE SEVENTEENTH CENTURY (CONTINUED). 



PACK 



Newton's Discovery of the Dispersion of Light — Traces the 

 amount of Refraction of each of the Coloured Rays — Makes a 

 Rotating Disc turning the colours of the Spectrum into White 

 Light — Reason why all Light passing through glass is not 

 Coloured — Mr. Chester More Hall discovers the Difference of 

 Dispersive Power in Flint and Crown Glass — Newton's Papers 

 destroyed by his pet dog — Last years of Newton's life . .164 



CHAPTER XXL 



SCIENCE OF THE SEVENTEENTH CENTURY (CONTINUED). 



Roemer measures the Velocity of Light — Newton's Corpuscular 

 Theory of Light — Undulatory or Wave Theory proposed by 

 Huyghens — Invention of Cycloidal Pendulums by Huyghens — 

 Discovery of Saturn's Ring — Sound caused by Vibration of Air — 

 Light by Vibration of Ether — Reasons why we see Light — 

 Reflection of Waves of Light — Cause of Colour— Refraction 

 explained by the Undulatory Theory — Mr. Tylor's Illustration 

 of Refraction — Double Refraction explained by Huyghens — 

 Polarisation of Light not understood till the nineteenth century . 1 72 



CHAPTER XXn. 

 Summary of the Science of the Seventeenth Century . 182 



CHAPTER XXIIL 



SCIENCE OF THE EIGHTEENTH CENTURY. 



Great spread of Science in the Eighteenth Century — Advance of 

 the Sciences relating to Living Beings — Foundation of Leyden 

 University in 1574 — Boerhaave, Professor of Medicine at Ley- 

 den, 1 701 — Foundation of Organic Chemistry by Boerhaave — 

 Influence of Boerhaave upon the study of Medicine — Belief of 

 the Alchemists in * Vital Fluids ' — Boerhaave's Experiments on 

 the Juices of Plants — Dr. Hales's Experiments on Plants — Boer- 

 haave's Analyses of Milk, Blood, &c. — Great popularity of his 

 Chemical Lectures 189 



