OP ARTS AND SCIENCES. 



307 



The condensation product thus has the formula CisHigOc, instead of 

 CigIIicOg ; by saponification with alcoholic potash two molecules of 

 alcohol are split off, as follows : 



CisHisOe + 2 H.O ^ Ci JlioOg + 2 CJIfiO. 



The above mentioned dibasic acid has therefore the formula 

 C14H10OG, instead of CuIIioOc, and indeed the previous analyses 

 aofree better with this formula. 



Benzo-p-difurfaron a-dimethyl ^-dicarhoxylic Ether, 



H O 



CO2C2H6 



H,C 



co^aHg. 



When quinone (one molecule) is heated in alcoholic solution with 

 two molecules of acetoacetic ether in the presence of zinc chloride, 

 the condensation product CigHigOe is obtained, and as regards prop- 

 erties, etc., I can confirm in all detail the given statements. The 

 alcoholic mother liquors contain, however, hydroquinone as well as a 

 new substance, C12H12O4, described below, which products have been 

 overlooked. The analysis of the condensation product crystallized 

 from acetic acid, gave figures agreeing well with the formula CigHigOe. 

 For the combustion it was carefully mixed with powdered chromate 

 of lead, and the results obtained prove that it contains about 2% 

 more carbon than found by v. Pechmann. The benzofurfuran de- 

 rivatives all burn with great difficulty, so that most of the analyses 

 given in this paper were carried out with lead chromate. 



0.1942 gram substance dried at 130° gave 0.4625 gram COg and 



0.0983 gram HaO. 

 0.2027 gram substance dried at 130° gave 0.4840 gram CO2 and 



0.1033 gram Hp. 



