OP ARTS AND SCIENCES. 163 



Sodic I^Z-Dihrompyromucate, NaC.HBr^O.. . 2 HjO. — The sodium 

 salt we prepared by dissolving the acid iu a solution of sodic carbonate, 

 and subsequent recrystallization from water. It formed short needles, 

 which were not very soluble in cold water, and which, when air-dried, 

 contained two molecules of water. 



I. 1.0207 grm. of the air-dried salt lost at 122° 0.1095 grm. H.p. 

 II. 1.1177 grm. of the air-dried salt lost at 122° 0.1201 grm. H^. 



H,0 



I. 0.5364 grm. of the anhydrous salt gave on ignition with H^SO^ 

 0.1284 grm. Na^SO,. 

 II. 0.5492 grm. of the anhydrous salt gave on ignition with HjSO^ 

 0.1314 grm. Na^SO,.' 



Na 



Potassic j^h-Dibrompyromticate, KCgHBr.iOg. — The potassium salt 

 prepared by dissolving the acid in a dilute solution of potassic car- 

 bonate, and recrystallizing the product thus obtained from water, crys- 

 tallized in long concentrically grouped needles, which proved to be 

 anhydrous. 



I. 0.5986 grm. of the salt gave on ignition with H^SO^ 0.1691 grm. 



K.,SO,. 

 II. 0.6018 grm. of the salt gave on ignition with H.,SO^ 0.1680 grm. 

 K,SO,. 



Calculated for Found. 



K0;IIBr..Og. I. II. 



K 12.69 12.69 12.53 



Ethyl /38-Dibrompyromucate,(C.,U.)C.UBr.p... — The ethyl ether we 

 have made by the action of etliyl iodide upon the silver salt of the 

 acid, and also by heating an alcoholic solution of the acid with concen- 

 trated sulphuric acid. By the latter method we have obtained a good 

 yield by dissolving five parts of the acid in an equal weight of abso- 

 lute alcohol, adding three parts of concentrated sulphuric acid, and 

 warming for several hours at 100°. The product precipitated by the 

 addition of water we washed with a dilute solution of sodic carbonate 

 and purified by recrystallization from alcohol. It crystallized in small, 



