LIST OF ILLUSTRATIONS 



t IG. PAGE 



1. Cubic Crystal of Salt 3 



2. Crystal of Saltpetre 4 



3. Sal-ammoniac ...... . . . 4 



4. The Colenso Diamond ....... 5 



5. Crystals of Quartz '...". . 6 



6. Arrowhead Crystals of Marcasite . . * ... 8 



7. Nodule of Marcasite as described by Glauber . . 9 



8. Striated Cubes of Pyrites 9 



9. Crystal of Blue Vitriol or Sulphate of Copper . 1 7 

 io. Large 'Crystal of Gypsum or Selenite (Sulphate of 



Lime) 19 



11-14. Mayow's Apparatus . . . . . . . 33 



15. Lavoisier's Apparatus for Calcining Lead and Tin in 



Air over Water or Mercury ..... 34 



16. Lavoisier's Apparatus for Heating Mercury in a 



Limited Volume of Air 41 



17. Cavendish's Apparatus for finding the Weight and 



Density of Gases . . . . 68 



1 8. Apparatus Used by Cavendish to Prepare a Gas 



which " Lost its Elasticity by Contact with 



Water" . . . 82 



19 (a). Hales's Apparatus for Measuring the Volume of 

 Gas set free by Heating Animal, Vegetable, and 



Mineral Substances . 85 



19 (). Hales's Apparatus (Improved Design) ... 85 



20. Priestley's Apparatus (First Plate) .... 87 



