206 PROCEEDINGS OF THE AMERICAN ACADEMY 



cent of the theoretical amount, as our average product, although in 

 single instances our yield has reached 50 per cent. The product 

 made in this way crystallized from water in well-formed rhombic 

 plates, which in their properties agreed in every particular with the 

 description of Schmelz and Beilstein. The acid melted at 125°, and 

 was very soluble in alcohol or ether, sparingly soluble in cold water, 

 readily in hot. Boiling benzol or chloroform dissolved it with readi- 

 ness, while in carbonic disulphide or ligroin it was almost insoluble. 

 The purity of our material was shown by the following analyses : — 



L 0.7408 grm. substance gave 0.7617 grm. COj and 0.0831 grm. 



H,0. 

 II. 0.5512 grm. substance gave 0.5687 grm. COj and 0.0621 grm. 

 H,0. 

 TIL 0.2090 grm. substance gave 0.3564 grm. AgCl. 



ni. 



42.16 



Although mucochloric acid appears to form derivatives in some 

 respects more stable and readily studied than the corresponding deriv- 

 atives of mucobromic acid, we bave thus far taken up more in detail 

 only the dichloracrylic acid which may easily be made from it by the 

 action of alkalies. 



DicJiloracrylic Acid. 



In 1877, "Wallach* obtained a dichloracrylic acid as a product of the 

 reduction of chloralid. This acid was afterward more carefully 

 studied by Wallach and Hunaus,t and quite recently Wallach | has 

 published a paper still further describing the acid and its salts, and 

 correcting the work of Iluntius in several important particulars. At 

 the time this investigation was begun, this acid was tlie only disubsti- 

 tuted acrylic acid known, and since its constitution was fairly established 

 by the mode of its preparation, it seemed desirable to prepare the 

 dichloracrylic acid from mucochloric, in order to compare the two 

 acids. 



* Berichte der deutsch. chem. Gcsellsch., viii. 1580. 



t Ik'richte der deutsch. ehem. Gesellsch., x. 507. Ann. Chem. u. Pharm. 

 cxciii. 19. 



I Ann. Chem. u. Pharm. cciii. 83. 



