266 PROCEEDINGS OP THE AMERICAN ACADEMY 



us of great interest, and we laid out what we thought would be time 

 enough for its investigation ; unfortunately, however, this was not the 

 case, since, after the work had been going on for some time, we found 

 that at least two substances were formed by this reaction, and conse- 

 quently the end of the term surprised us before we had reached any 

 definite results. We have decided, however, to publish here what 

 results we have obtained, as we are unable to go on with this work 

 together, but wish it to be understood that all these statements are 

 to be taken as preliminary. 



If about 1 gr. of bromtrinitrophenylmalonic ester was mixed with 

 2-3 c.c. of strong nitric acid (specific gravity 1.36), no change took 

 place in the cold ; but if the mixture was warmed gently on the water 

 bath for less than five minutes, an intense vivid red color appeared 

 in both the acid liquid and the organic substance, which melted and 

 became converted into a viscous mass. If now the acid was poured 

 off, a fresh quantity added, and the gentle warming repeated, the vis- 

 cous drop became converted into a red crystalline mass, and by con- 

 tinuing* this treatment with successive portions of nitric acid the red 

 color could be removed partially, so that the product had a spotted red 

 and white appearance. This frequent treatment with nitric acid was, 

 however, unnecessary, as the red crystalline product after the second 

 warming with nitric acid gave, when crystallized from alcohol, well 

 formed white prisms, and a reddish mother liquor. The red nitric acid 

 poured off from the principal part of the product gave with water a 

 red precipitate, but a better mode of treatment seemed to be to evapo- 

 rate this red acid to dryness on the water bath. The residue, or pre- 

 cipitate obtained with water, was partly viscous, partly crystalline, 

 and by treating it again with warm strong nitric acid a new quantity 

 of the red crystalline substance was obtained, but the amount recov- 

 ered in this way was so small that it hardly paid for the trouble. 

 The white crystals, after purification by crystallization from alcohol, 

 showed the constant melting point 125°, and their behavior in melting 

 was very characteristic, as they turned from white to bright red, and 

 swelled to many times their original volume. They were not affected 

 by sodic hydrate in aqueous solution. Supposing that the substance 

 was homogeneous because of its constant melting point, we analyzed 

 it, but on studying its properties more carefully we began to doubt its 

 purity for the following reasons : — First. Although the microscopic 

 examination showed that the substance consisted principally of white, 

 short, rather thick monoclinic prisms, usually with both terminations 

 well developed and made up of two planes, there were mixed with 



