194 PROCEEDINGS OP THE AMERICAN ACADEMY 



furfurol with argentic oxide, gave us little hope that we could in 

 this way conveniently prepare large quantities of methylpyromucic 

 acid, no hetter method suggested itself to us at the time, and we 

 were forced to adopt it. To our surprise, we found that we could 

 easily obtain in this way a weight of methylpyromucic acid which 

 nearly equalled that of the aldehyde taken, and that we could also 

 obtain from furfurol under the same conditions an equally satisfac- 

 tory yield of pyromucic acid. From methylfurfurol we obtained as 

 a maximum 84 per cent of the theoretical yield of methylpyromucic 

 acid, from furfurol 82 per cent of the calculated amount of acid. 

 As the weight of acid remaining in solution after precipitation 

 with hydrochloric acid was in neither case taken into account, the 

 reaction may fairly be called quantitative. The large yield which 

 we obtained was doubtless due in part to a slight modification of 

 the ordinary method of procedure, which we shall presently de- 

 scribe. Still we had no difficulty in obtaining from 10 grm. of fur- 

 furol in the usual way 8.5 grm. of argentic pyromucate, and from 

 the acidified mother liquor by extraction with ether 2.9 grm. of pyro- 

 mucic acid, so that the total yield of pyromucic acid in this case 

 was 7.25 grm., or 62.1 per cent of the theoretical amount. All the 

 methylpyromucic acid which we have used in our investigations we 

 have made by the following method. 10 grm. of methylfurfurol 

 were added to about 50 grm. of well washed argentic oxide sus- 

 pended in about 800 c.c. of hot water, and the whole heated quickly 

 to boiling. When the reaction appeared to be complete, pure 

 sodic carbonate was added in quantity sufficient to precipitate the 

 silver which had been carried into solution, and the feebly alkaline 

 solution again boiled. When the fresh well marked reduction which 

 then ensued was finished, the solution was filtered, evaporated to 

 small volume, again filtered, and acidified with hydrochloric acid. 

 The acid which separated as the solution cooled was nearly color- 

 less, and as a rule a single rec^stallization was sufficient to raise 

 the melting point to the proper point. The slight color could be 

 most conveniently removed, if necessary, by treating a solution of 

 the calcium salt with bone-black. 



0.2007 grm. of the acid gave 0.4321 grm. C0 2 and 0.0900 

 grm. H 2 0. 



Calculated for C 6 H 6 3 . Found. 



C 57.14 57.01 



H 4.76 4.84 



