310 INDEX. 



Solids, the specific heat of compound, generally greater than that of their 



component elements, i. 101 

 Solorina, structure of the genus, i. 305 

 Solorina crocea, structure of, i. 306 

 Solorina saccata, structure of, i. 305 

 Space, matter wandering in, i. 28 



Spearmint, absorption of radiant heat by the perfume of, i. 44 

 Specific gravity, i. 26 



unit of, i. 26 



Spectra, continuous, from glowing solids and liquids, i. 132 

 spectrum analysis, i. 133 



experiments of Sir David Brewster and Mr. Fox Talbot, i. 133 

 spectrum of rubidium and caesium, i. 136 

 of thallium, i. 136, 137 

 of indium, i. 137 



of the flame of the iron in the manufacture of the Besse- 

 mer steel, i. 137, 138 

 of gases, i. 139, et seq. 



effect of high temperature on various spectra, i. 142- 



144 

 effects of pressure on a variety of gases and vapours, 



i. 145 



of metals not always the same, i. 145 

 of the halogens, i. 146 



of the vaporized mixture of five chlorides, i. 147 

 of lightning, 147 

 of the sun. See Solar spectrum 

 of the fixed stars, i. 155, 162, 163 

 of temporary and periodic stars, i. 156, 157 

 of the planets,!. 157, 158, 161 

 of various nebulae, i. 158-160 

 Spermatozoidsof confervacese, i. 210 

 Sphaeria aquila, structure and habitat of, i. 295 

 Sphseria bombarda, structure of, i. 295 

 Sphseria, candle-snuff, habitat of, i. 295 

 Sphseria Desmazierii, development of, i. 294 

 Sphseria miliaris, characters of, i. 283 

 Sphseriacei, characters and habitat of the order, i. 293 



development of, i. 294 



Sphserobolus, force with which its sporangium is ejected, i. 273 

 Sphaerococcoidese, characters of the, i. 238 

 Sphserococcus coronopifolius, mode of reproduction of, i. 236, 238 



