OF ARTS AND SCIENCES. 209 



These determinations give as the percentages of the anhydrous salt 

 contained in the hot solutions saturated at 18° and 18°.5 respectively 



I. II. 



6.28 6.19 



Calcic Dichloracrylate, Ca(C3HCl202)2-3H20. The calcium salt, 

 which was extremely soluble in water, was made by neutralizing a 

 solution of the acid with calcic carbonate. On cooling the concen- 

 trated solution, the salt separated in long, flat radiating needles, which 

 were permanent in the air, but slowly effloresced over sulphuric acid. 



I. 0.4077 grm. of the air-dried salt lost, on heating to 95-100°, 

 0.0580 grm. HgO, and gave, on ignition with H^SO^, 0.1488 

 grm. CaSO^. 

 11. 0.61&3 grm. of the air-dried salt lost, on heating, 0.0875 grm* 

 H,0. 

 III. 0.3217 grm. of the dried salt (II.), corresponding to 0.3749 

 grm. of the air-dried salt, gave, on ignition with HgSO^, 0.1348 

 grm. CaSO^. 



Potassic Dichloracrylate, KCgllCljOg. The potassium salt crystal- 

 lizes from a solution of mucochloric acid in an excess of potassic 

 hydrate (1 : 4) when this is strongly cooled. Although it is quite 

 soluble even in cold water, it may readily be purified by recrystalliza- 

 tion from hot water. From concentrated solutions it crystallizes on 

 cooling in long, slender needles, which are anhydrous. 



I. 0.3054 grm. of the salt gave, on ignition and evaporation with 



HCl, 0.1283 grm. KCl. 

 II. 0.2159 grm. of the salt gave 0.0908 grm. KCl. 



The foregoing results seemed to us to show with sufficient precision 

 that our acid was essentially different from the /? dichloracrylic acid 

 of Wallach, since the two acids differed markedly in their physical 

 properties, and their salts were also quite dissimilar. Following the 



