320 PROCEEDINGS OF THE AMERICAN ACADEMY 



XXYI. 



CONTRIBUTIONS FROM. THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



I. ON CHLORPYROMUCIC ACIDS* 

 By Henry B. Hill and Louis L. Jackson. 



Presented May 28, 1889. 



Many years ago Malaguti f found that dry chlorine gas was quickly 

 absorbed by ethyl pyromucate, and that a thick viscous liquid was 

 formed, the composition of which showed that four atoms of chlorine 

 had been taken up. The oil was carbonized on distillation, and 

 yielded with potassic hydrate decomposition products which were not 

 further studied. Although Schmelz and Beilstein t later found that 

 chlorine converted pyromucic acid in aqueous solution into muco- 

 chloric acid, and this reaction was afterwards further studied by Hill 

 and Bennett,§ no further experiments, as far as we could learn, had 

 ever been made with dry chlorine on pyromucic acid or its ethers. 

 In 1884, after it had been shown by investigations carried on in 

 this laboratory that substitution products could readily be formed 

 from pyromucic acid by the action of dry bromine, Mr. J. N. Garratt, 

 at that time an assistant in the laboratorv, undertook the investigation 

 of the action of dry chlorine under similar conditions. Although he 

 succeeded in isolating a dichlorpyromucic acid melting at 167-168° 

 in a state of purity, he found that the reaction differed in many re- 

 spects from the corresponding reaction with bromine, and that the 

 matter deserved a more careful study than he was then able to bestow 

 upon it. Mr. Garratt relinquished his investigation of this subject in 

 order to continue his studies in Zurich, and in the following winter 



* A part of the work described in the following paper was presented in the 

 form of a thesis to the Academic Council of Harvard University in May, 1888, 

 by Louis L. Jackson, then candidate for the degree of Doctor of Philosophy. 



t Ann. Chim. Phys., Ixiv. 282; Ixx. 371. 



t Ann. Chera. u. Pharm., Suppl., iii. 276. 



§ Berichte d. deutsch. chcm. Gesellsch., xii. 655. 



