IXDEX. 259 



Atoms : effect of catalysis, i. 91 

 of matter, i. 2 

 cohesion of, i. 25 

 unit of mechanical force, i, 26 

 the atomic theory, i. 93 

 the law of definite proportions, in combination and resolution of the 



component parts of substances, i. 94 

 affinity of kind and of degree, i. 95 

 force of chemical combination, i. 97, 98 

 relative atomic weights, i. 99 



table of atomic weights compared with that of hydrogen, i. 100 

 relation between the atomic weights and the specific gravities 



of substances, i. 100 



capacities of atoms for heat and electricity, i. 100, 101 

 law of equivalency in weight and volume, i. 102, 103 

 substitution the basis of this law, i. 104 

 sequence of atomic numbers, i. 105 



groups of substances whose atomic weights are in regular arithme- 

 tical series, i. 106 



groups of combined atoms called compound radicles, i. 106 

 the polyatomic theory, i. 107 

 the force of molecular attraction more powerful than gravitation, 



i. 109 



internal movement of molecules of matter in a gaseous state, i. 113 

 Aulocantha scolymantha, structure of, ii. 21 



Avicula margaritacea, or pearl oyster, nacreous lining of shell of, ii. 234 

 Azores, the black mildew of the, i. 297 

 Azote in vegetable organisms, i. 423 

 Azuline dye, production of, i. 123 



B 



Babylon, the asphaltic mortar used in building, i. 126 

 Bacillaria cursoria, motion of, i. 203 

 Bacillaria paradoxa, motion of, i. 203 

 Back, Sir George, his arctic journey, i. 308 

 Bacteria, their structure, size and habitat, ii. 64 

 Baeomyces, structure of, i. 306 

 Balanidoe, structure of, ii. 213 

 Balanus balanoides, development of, ii. 216 



S 2 



