CONTENTS 7 



PAGE 



6. OPTICAL EELATIONS 77 



A. Velocity of light and refractive index . . . .78 



B. Influence of wave-length 78 



C. Effect of density 79 



D. Additive relations 80 



E. Dielectric constant 83 



//. RELATIONS BETWEEN CHEMICAL PROPERTIES 

 AND COMPOSITION. 



i. THE ELEMENTS BRING THE CHEMICAL PROPERTIES 

 THAT THEY SHOW IN SIMPLE BlNARY COMPOUNDS 

 INTO MORE COMPLEX DERIVATIVES ... .88 



A. Chemical character of the most important elements 



in their simple compounds 8 9 



1. Positive or metallic and negative or metalloid character . 89 



2. Evolution of heat in simple reactions . . 9 1 



3. Tendency to self-combination ....- 95 



4. Velocity of reactions 9 6 



Summary . . . . . . . -97 



B. Affinity of the elements in more complex compounds 98 



1. Additive character of the heat of formation . ... 98 



2. Constitution of explosives 103 



(a) Simple explosives ........ 104 



(5) Explosive mixtures 107 



Two elements 107 



Three elements . . . . . . . 108 



Four elements . . 109 



(c) Practical explosives , . . . . . .109 



(a) Solid mixtures ........ 109 



(j8) Liquid mixtures no 



(7) More complex compounds no 



2. THE INFLUENCE ON ELEMENTS ALREADY PRESENT IN 



A COMPOUND EXERTED BY ELEMENTS INTRODUCED . 113 



A. Introduction of the electro-affinity, i.e. of positive 

 or negative character, into the group into which 

 an element enters 113 



i. Influence of positive elements . . . . . .114 



(a) Influence of hydrogen . . . . . . .114 



(a) Hydrogen affects acidity 114 



