TRANSACTIONS OF SECTION B, 



621 



one from the Saxon Erzgebirge given by Sauer. These seem to complete the 

 transition from asphalt to graphite. 



Composition of Precarboniferous Coals calculated on the Dry Substance free from 



Ash. 



3. The Constitution of Aliphatic Ketones. By Professor P. C. Freer. 



4. Tlie Chemistry of Methylene. By Professor J. U. Nef. 



5. Formation of a Benzene-Ring hy Redicction of a \ -.Q Diketon. 



By A. Lehmann. 



The 1 : 6 diketon was formed by condensation of benzil -with two molecules of 

 acetophenoB, the former partially dissolved in the latter, and condensed with 

 alcoholic solution of sodium hydrate (yield 80 per cent.). 



C„H, 



C: O 



I - 

 C: 



C«H, 



CsHj 



CHa.CO.C^H 



ch,.co.c,h; 



C : CH.CQ.CH, 



6"s 



5 = 2H,0+ i 



C : CH.CO.C.Hj 



C„H, 



This by reduction with HI gave, together with other substances, a small 

 yield (1 per cent.) of tetraphenyl- benzene. A ring formation therefore took place 

 to some extent. Much better results were, however, obtained by reduction with 

 zinc dust and acetic acid, and treating one of the products with phosphor-oxy- 

 chloride. 



The zinc-dust reduction gave a butylen derivative (diphenyl-dibenzoyl-butylen> 

 a pinakon, a ' pinakolin,' and several other products. The butylen derivative gave 

 ■with POCI3 40 per cent, of tetraphenyl-beuzene. The latter reaction is a very 

 interesting one — so far as I know without a direct parallel. The ' pinakolin ' 

 strictly speaking, does not belong to this class. It is not a keton, but, most likely 

 a derivative of a compound standing in the same relation to benzene as ethylen to 

 ethylen-oxide. 



H 

 C 



C.H-C 



// 



C5F5 — C 



c 



H 



C-C.H, 



