INDEX, 





Stahl, chemical theory of 52 



Stems lu'iitt to indigo rays 413 



Sti>k.'> mi e|e,-trie liijlil l'2't 



Strontian, Hume of 55 



Suliitiiiion, theory of 104 



Sun, force derived t'nun I-V 



" surface of, its condition 81-88 



Swan on yellow my 63 



Systemic circulation ;57<> 



T. 



Thermo-electric couples 827 



" currents 328 



" " pairs, effect of num- 

 ber of 334 



" " pairs, improved 



forms of :.:.; 



" quantity "M:\ 



" " thermometer .'J'-'T 



Thickness, effect of, in sensitivene>- 



Tiili-s in mercury 346 



Towson on camera 211 



Transmission from retina to brain. . . Hi'.' 



Tyndall on distribution of heat 385 



" on electric light 3W 



" on ignition of platinum !:'>'' 



" on spectrum 384 



U. 



Undulations and colors 123 



" interpretation of, by 



brain 122 



" length of. l-'l 



Undulntory theory, power of the 117 



Unit lamp 45 



V. 



Vertical clement of flame analyzed.. 65 

 Vibrations coimci-t.-d with tempera- 

 ture 36 



" "f, on retina 1<>H 



" spectrum meaxure of . . . 



Virginia, CXJ-IM iin.-nis made in l'.7 



sjicctrum - 



Vision and photographic impressions. 210 



" hypothesis of ln| 



" inverse II! 



Vital force, rejection of 



Vogel, 1'rofessor, on increased sen- 

 Mti\eness 4.".1 



\V. 



Water, decomposition of. 188 



" decomposition of, under press- 

 ure 363 



" not decomposed by light i".U 

 Wave-lengths as spectrum meas- 



ui-es 11::. IL'7 



" " interpretation of, by 



brain ". 1L"J 



" " measures of 121 



Wedgwood on ignition of gold and 



earthenware 28 



Wilson's experiments on phospho- 

 ri... .. 318 



Wollaston on spectnim 88 



Y. 



Yellow ray most luminous 1 '>" 



Young discovers interference 116 



THE END. 



