134 



Prof. T. Carnelley on the Col 



our 



It must be remarked that the above rule applies only to 

 those cases in which A, B, C, &c. are elements belonging to 

 the same subgroup, as: — CI, Br, and I ; Na, Cu, Ag, and Au ; 

 Mg, Zn, Cd, and Hg ; Be, Ca, Sr, and Ba ; Al, Ga, In, and 

 Tl ; 0, Cr, Mo, W, and U ; P, As, Sb, and Bi; &c. ; but not 

 in those cases in which they belong to different subgroups. 

 Thus oxides cannot strictly be compared with the corresponding 

 sulphides, selenides, and tellurides, nor fluorides with the cor- 

 responding chlorides, bromides, and iodides, &c. ; for F and 

 are elements belonging to even series, whereas CI, Br, I, 

 and S, Se, Te belong to odd series. 



The Tables given below will illustrate the colour-relations 



Table of Colour Relations 

 (showing the influence of atomic weight). 









1 





R. 



RC1. 



RBr. 



EI. 



i 



R 2 S. 



R 2 Se. 



R 2 Te- 



RF. 



> white 



red 

 brown 



{ 



R 2 o w 



Na- 

 du... 

 Ag... 



Au{ 



white 



white 



white \ 



yellow- 

 ish-white 



white 



grey 



yellow- 

 ish-white 



yellow- 

 ish-grey 



white \ 



L 



cream 



light | 



yellow j 



golden "1 

 yellow J 



flesh- 

 coloured 



black 

 black 



black 



| red { 

 black 



dark 

 coppery 



black 



grey 



red 



brown 



violet-brown 

 green 





*> 





! 



I 





R. 



R 2 S0 4 . 



R 2 Se0 4 . 



R 2 Te0 4 . 



R 3 As0 3 . 



white 



R 3 As0 4 . 



white 



R 3 AsS 4 . 



R 3 SbS r 



R 2 Cr0 4 . S 



Ha... 



white 



white 



white 



yellow 



f pale 

 \ yellow 



> yellow 



Cu- 

 Ag- 



white 



white \ 



dark 



yellow 



I yellow 



red 



brown 



black 



red 



Au... 





















*» 



^ 





1 



R. 



RC1 2 - 



RBr 2 . 



RI 2 . 



RS. 



RSe. 



RTe. 



RO. 



R 3 n 2 . 



Mg... 

 Zn ... 



Cd- 

 Hg- 



white 

 white 



white 

 white < 



white 

 white 



white 



white, c. 

 yellow, h. 



white 

 white 



white 



yellow 

 red 



white 

 white \ 



yellow 



red 

 black 



lemon- 

 yellow 



steel- 

 grey 



] g re y { 



i 



i 1 



white 



white, c. 

 yellow, h. 



brown, 

 red when 

 crystalline 



orange - 

 yellow 

 red 



f greenish- 

 \ yellow 



I green 



) 



1 dark 

 j brown 



