3 o8 INDEX. 



Sea-serpent of Celebes, ii. 186 



Sea-slugs, structure of, ii. 239, 240 



Sea- weeds, former and present uses of, i. 128 



Seeds of two lobes, i. 177 



of one lobe, i. 177 



of plants, i. 381, 382, 383,404 

 Selaginella, structure and habitat of, i. 374 

 Selenium, atomic weight of, i. 105 



its properties analogous with those of sulphur and tellurium, i. 105 

 Sepedonium mycophilum, spores of, i. 286 

 Sepia, or cuttle fish, structure of, ii. 245, 246, 247 

 Serpentine marble of Tyree and of Connemara, composition of, ii. 56 

 Serpula, structure of, ii. 155 

 Sertularia cupressina, structure of, ii. 87 

 Sertulariidse, characters of the family of, ii. 90, 91 



modes of propagation of, ii. 91 

 Shells of mollusks, ii. 234 

 Shrimps, opossum, ii. 199, 200 

 Sigillaria, structure of the fossil, i. 375 

 Silex, quantity of, in the Equisetaceae, i. 369 



in the grasses, i. 386 

 Silica, abundance of, i. 17 



in the stalks and leaves of the grasses, i. 386 



effect of electricity on, i. 32 

 Silicon, i. 17 



combined with oxygen gas forms rock-crystal, i 17 



three different states in which it exists, i. 18 



analogy between silicon and carbon, i. 1 8 



Professor Graham's limpid solution of, i. 18 

 Silk, dyes for, i. 125 



mode of preparing it if it is to be moire, i. 125 



advantages of the climate of Lyons in the manufacture of, i. 126 

 Silk-worm, a fungus parasite of the, i. 274 

 Silver, affinity of, for oxygen, i. 5 



conduction of heat and radiation, i. 5 



iodine found in combination with, i. 19 



crystals of, formed artificially by electricity, i. 74 



transmissive power of, of electricity, i. 90 



Sipunculidse, structure and mode of reproduction of, ii. 186, 187 

 Sky, probable cause of the blue colour of the, i. 58 

 Slate, polishing, of Bilin, of what it consists, i. 206 

 Smoke, i. 14 



