4;>G C. PIAZZI SMYTH ON MICROMETRICAL MEASURES OF 



aiiee into constituents physical, or constituents chemical, of the CO, was accomplished hy the 

 spark ; and the tetravalence of Carbon unsatiated ly the bivalence of Oxygen, or in other words 

 the propriety that chemists admit (our chemical Professor, Dr Bedson, just now suggests to 

 me) of regarding Carbon as sometimes divalent like Oxygen in forming neutral combinations 



such as CO, may be the origin of / c P = =0 ° e = r O" \ the double structure 



\ Tttravalent Carbon. Divalent Carbon. / 



of this CO linelet band. At any rate it will interest me very much to see if I can make 

 better sense now, and trace some similar evidence, of duality perhaps in other " Carbon " records 

 of the CO citron, and Blow-pipe-green Band-lines that I have, distinctly enough measured I 

 daresay to tell the same tale if they are carefully interrogated. 



A. S. H. 



