CONTENTS 



Jl -ixJuuX J- 



TEE CONSTITUENTS, PHYSICAL AND CHEMICAL 

 PBOPEBTIES, AND MODE OF OCCUBBENCE 



OF BOCKS 



PAGE 



I. Introductory: Books Defined 1 



II. The Chemical Elements constituting Books ... 4 



III. The Minerals constituting Bocks 9 



IV. The Physical and Chemical Properties of Bocks . . 30 



1. Tlie Structure of Boeks, macroscopic and microscopic 30 



2. Tlie Specific Gravity of Bocks 40 



3. The Chemical Composition of Eocks .... 41 



4. The Color of Bocks 42 



V. The Mode of Occurrence of Bocks 45 



PART II 



THE KINDS OF BOCKS 

 Generalities, and Classification '52 



L Igneous Bocks: Origin op, and Classification; Belation- 



ship existing between Plutonic and Effusive Bocks 55 



1. The Granite-Liparite Group 61 



2. The Syenite-Trachyte Group 68 



3. The Poyaite-Phonolite Group 73 



4. The Diorite-Andesite Group 76 



5. The Gabbro-Basalt Group 80 



6. The Theralite-Basanite Group 88 



xi 



