CONTENTS. 



PART II. 



SCIENCE OF THE MIDDLE ACES. 



CHAPTER VI. 



SCIENCE OF THE ARABS. 



PAGB 



Dark Ages of Europe The Arabs, checked in their conquests by 

 Charles Martel, settle down to Science The Nestorians and 

 Jews translate Greek Works on Science Universities of the 

 Arabs Chemistry first studied by the Arabs Alchemy, or the 

 attempt to make Gold Hermes the first Alchemist Hermeti- 

 cally-sealed Tubes Gases and Vapours called ' Spirits' by the 

 Arabs . . 39 



CHAPTER VII. 



SCIENCE OF THE ARABS (CONTINUED). 



Geber, or Djafer, the founder of Chemistry His Explanation of 

 Distillation Of Sublimation Discovers that some Metals in- 

 crease in weight when heated Discovers strong Acids Nitric 

 Acid Sulphuric Acid Discoveiy of Sal-Ammoniac by the 

 Arabs Arabs mix up Astronomy with Astrology Albateg- 

 nius calculates the Length of the Year Mohammed Ben 

 Musa, first writer on Algebra Uses the Indian Numerals 

 Gerbert introduces them into Europe Alhazen's discoveries in 

 Optics His Explanation why only one image of each object 

 reaches the Brain His discovery of Refraction, and of its 

 effect on the light of the Sun, Moon, and Stars His discovery 

 of the magnifying power of rounded glasses . . 43 



CHAPTER VIII. 



SCIENCE OF THE MIDDLE AGES IN EUROPE. 



Roger Bacon His 'Opus Majus' His Explanation of the Rain- 

 bow He makes Gunpowder Studies Gases Proves a Candle 

 will not bum without Air His Description of a Telescope 



