MR. WATSON SMITH ON ISODINAPHTHYL. 13 



II. On IsodinaphthyL By Watson Smith, F.C.S. Com- 

 municated by Professor H. E. Roscoe, Ph.D., F.R.S. 



Read November 29th, 1870. 



Instead of at once dealing with the main subject of this 

 paper, I think a brief view of certain of the results of re- 

 searches of several eminent chemists, directly bearing on 

 the matter in hand, would be at once interesting and de- 

 sirable. 



The peculiar hydrocarbon diphenyl was first obtained 

 by Fittig* by treating monobrombenzol with sodium : 



2C 6 H 5 Br+2Na=2NaBr + £ 6 ^ 5 |. 



Now Berthelotf, in the year 1866, by passing benzol 

 vapour through a porcelain tube heated to bright redness, 

 obtained diphenyl as the chief product of decomposition. 

 Bcrthelot distinctly says, " The body so obtained is a beau- 

 tifully crystalline substance, which is identical with Fittig's 

 diphenyl, possessing exactly the melting- and boiling-points 

 given by Fittig, and agreeing generally with that body." 

 A small quantity of chrysene is also said to be formed, 

 and of a solid resinous body, of an orange colour, whicli 

 is but slightly soluble in alcohol, rendering the same fluor- 

 escent. The formula 



Diphenyl. 



represents this decomposition. 



I. About the commencement of the year 1867 J, Dr. 



* Ann. d. Ch. und Ph. exxi. 361, and exxxii. 201. 

 t Zeitsch. f. Chemie, 1866, Dec. 14, p. 707. 

 X Ann. d. Ch. und Pharm. Band cxliv. p. 71. 



