INDEX. 255 



Agaricus olearius, luminosity of, i. 264 

 Air, a non-conductor of electricity, i. 32 



amount of fores exerted by the sun's light within the limits of the 

 terrestrial atmosphere, i. 34 



absorption of radiant heat by, i. 41 



effect of the rays of the sun falling on the earth through pure dry 

 air, i. 53 



spectrum analysis of the component parts of the atmosphere, i. 139 

 Air-vessel of Nereocystis Lutkeana, i. 249, 250 

 Alaria esculenta, fruit of, i. 249 

 Alaria Pylaii, fruit of, i. 249 



Albumen, formation and structure of, in vegetable organisms, i. 423 

 Alcohol, chemical combination forming, i. 97 

 Alcyon zoophytes, characters of, ii. 119, 120 



structure and mode of reproduction of, ii. 120-123 

 Alcyonidium elegans, structure of, ii. 120 



Alcyonium digitatum, or dead man's fingers, structure of, ii. 121, 122 

 Aldebaran, spectrum of, i. 155 

 Algae, i. 179 



classification of the group, i. 179-181 



green Algae, i. 181-220 



zones or degrees of depth at which different Algae exist, ii. 221, 258, 

 259 



brackish water often a cause of change in the form of Algae, i. 245 



colossal Algae of the North Pacific, i. 245 



rings of growth of some of the larger sea-weeds, i. 252 

 Alizarine blue, from what obtained, i. 124, 125 

 Alkalies, their affinity for acids, i. 96 

 Alkaloids, chemical structure of, i. 427 



Allosorus crispus, or parsley fern, structure and habitat of, i. 358 

 Allotropism, i. 8 



of carbon, i. 15 

 Alsophilse, structure of, i. 360 

 Alum, a free radiator but a bad conductor of radiant heat, i. 37 



partial decomposition of, by diffusion, i. 109 



manufacture of, i. 120 

 Alumina, effect of electricity on, i. 32 

 Aluminum, i. 4 



spectrum of, i. 65 

 Amalgams of metals, illustrating the relation between chemical affinity 



and mechanical force, i. 98 

 Amansia, structure of, i. 242 



