158 PROCEEDINGS OF THE AMERICAN ACADEMY 



by oxidation any products which would enable us to draw any conclu- 

 sion as to its constitution. 



The solid which separated from the higher fractions, on cooling 

 when recrystallized from alcohol, formed broad flattened needles which 

 melted at 77°. It was readily soluble in alcohol, ether, chloroform, or 

 benzol, more sparingly soluble in carbonic disulphide or ligroin. The 

 percentage of bromine which the substance contained agreed precisely 

 with that required by the formula C^HgBrO.^. While the combustion 

 of the substance gave a pei'centage of carbon materially greater than 

 that which this formula requires, it seemed to us to leave no doubt of 

 the composition of the substance. We were therefore unwilling to sac- 

 rifice the small amount of the substance which we had left in order to 

 make a second combustion. 



I. 0.5251 grm. of substance (F) gave 0.5742 grm. CO^ and 0.0949 

 grm. HgO. 

 II. 0.1523 grm. of substance (B) gave 0.1758 grm. AgBr. 

 III. 0.2186 grm. of substance (F) gave 0.2527 grm. AgBr. 



III. 



49.19 



The small amount of this substance at our disposal — we obtained but 

 three grammes of the crude product from 2.G kilogrammes of pyro- 

 mucic tetrabromide — has made it impossible for us to submit it to 

 anv very extended investigation. In aqueous solution it reduces silver 

 oxide, and at the same time argentic bromide is formed. We were 

 unable, however, to isolate any definite products of the oxidation. 

 With nitric acid, apparently nothing but oxalic acid was formed. It 

 was unaffected by dry bromine, but when treated with bromine and 

 water it was converted into an amorphous substance insoluble or spar- 

 ingly soluble in all common solvents. It was readily decomposed by 

 aqueous alkalies. The solution had a bright yellow color, and con- 

 tained potassic bromide, but we have been unable to determine the 

 products resulting from the reaction. 



This ready decomposition in alkaline solution makes it probable 

 that it was formed during the process of distillation, although it is 

 perhaps possible that the small quantity which we were able to obtain 

 was only that portion which chanced to escape decomposition in the 



