xx.j THE CASE OF GOLD. 279 



Absorption in the blue (continued.} 



Tin (red also), 

 Lead (red also). 

 Antimony. 

 Gold (red also). 

 Palladium. 



A discussion of these observations at the temperature of the 

 oxyhydrogen flame with those made at the lower temperatures 

 seemed to prove beyond all question that the molecules which 

 absorbed the blue were broken up to produce the one with the 

 fluted spectrum, and similar reasoning indicated that the blue 

 molecules were produced at the expense of the red ones. 



The reasoning was the same as that which had been held to 

 demonstrate the different complexities of the molecules which 

 gave line and fluted spectra respectively. Unfortunately we were 

 in both cases almost beyond chemical and other physical inquiry 

 almost, but not quite ; and where other inquiry was possible, it 

 gave no uncertain sound. It is important that these other 

 inquiries should be referred to in some detail. 



In the case of gold it is possible to separate the blue and 

 red molecules, which I contend produce the colour of gold 

 leaf, and to get them into different bottles that ne plus ultra 

 of chemical separation. The beautiful researches of Faraday 

 on this substance led him to the conclusion that we were by the 

 colour phenomenon brought really into presence of a different 

 molecular structure, but he worked in the prespectroscopic 

 days, and each different colour to him represented a molecule. 

 Hence he held that the molecules existed " of intermediate sizes 

 or proportions." l I hold, however, that a twofold complexity 

 is sufficient to explain all the phenomena. We have absorp- 

 tion of the blue giving us red gold, absorption of the red giving 

 us blue gold, and absorption both of blue and red giving us 

 green gold. 



1 Researches in Chemistry, p. 417. 



