MR. WATSON SMITH ON ISODINAPHTHYL. 15 



much the same extent as alcohol does ; and it crystallizes 

 from the solution of that body in the same form as it does 

 from alcohol. Dinaphthyl melts at 154 C. Its boiling- 

 point lies above that of mercury. Robert Otto"* and Gustav 

 Mories repeated Lossen^s experiments with precisely the 

 same results ; but they tried, in order to get dinaphthyl 

 formed more easily, and in larger quantity, to form it by 

 first obtaining the mercury compound mercurio-dinaph- 



C TT 1 

 thyl pi^tt 7 r Hg",by heating monobromnaphthalin with so- 



dium amalgam (Na 2 Hg"), and raising this to a red heat with 

 soda lime in a porcelain tube. Mercury and a yellow 

 crystalline mass were obtained, the greatest portion of the 

 latter consisting of naphthalin. This yellow mass, on 

 boiling with alcohol, yielded on cooling the rhombic tables 

 of naphthalin abundantly, the mother liquors exhibiting 

 strong green fluorescence by reflected light, and furnishiug 

 on evaporation a yellow mass, which, after suitable puri- 

 fication, deposited from alcohol small canary-yellow shi- 

 ning leaf-like crystals, which melted at 133 C. This body 

 was readily soluble in alcohol, ether, and benzol. The 

 solution of the pure hydrocarbon was no longer fluor- 

 escent. 



They made a combustion, which did not seem to be 

 satisfactory, as they only had 0*066 grm. of substance to 

 work with, and of this they did not feel sure of the perfect 

 purity. The percentage composition they obtained almost 

 exactly corresponded with that of naphthalin. They con- 

 sider the action to be chiefly 



C] J } Hg" + H 2 = 2C 10 H 8 + HgO. 



About the close of the year 1866, Berthelotf concluded 

 his remarkable series of experiments on the action of cer- 



* Ann. d. Oh. und Ph. 1868, cxlvii. p. 164. 

 Zeitschrift f. Ch. 1867, Jan. 31st; and Compt. Rend, lxiii. 998 and 1077. 



