Potassium on Ethyl Succinate. 131 



2. Metallic Compomids. 



When sodium-amalgam is allowed to act upon the alcoholic 

 solution of the compound, there is produced a voluminous red 

 precipitate, which is very easily soluble in water. From the 

 aqueous solution, chlorhydric acid precipitates a white sub- 

 stance which is insoluble in water and difficultly soluble in alco- 

 hol. This substance proved to be the original compound. 

 The same red precipitate is produced when alcoholic solutions 

 of the compound and potassic hydroxide are brought together, 

 and a similar precipitate when sodic hydroxide is used instead 

 of potassic hydroxide. The latter precipitate was first pre 

 pared for examination. 



Sodium- Compound, C^^^^^I^^^Oq +4H2O. 



This compound was prepared by bringing together alcoholic 

 solutions of the original body and sodic hydroxide. It is 

 thrown down immediately, as a beautiful red precipitate. This 

 precipitate consists of microscopic needles. It was filtered off 

 and washed out with alcohol. In drying, the color changed 

 from red to yellow, but it appeai-s as though this change of 

 color is not accompanied by a chemical change. The analyses 

 gave the following results : 



I. 0-201 grams of the substance gave 0-08 grams NagSO^^r 



0'0259 grams Na. 



II. 0'1202 grams of the substance gave 0*048 grams NagSO^z^ 



0-0155472 grams Na. 



Calculated. Found. 



+4H2O. It is very easily soluble in water, and the body, 

 C,2H,gOg, is precipitated from this solution on the addition 

 of an acid. By boiling with a little sodic hydroxide succinic 

 acid is formed. 



The corresponding potassium compound is mentioned by 

 Wislicenus (loc. cit.) Another potassium compound of the 

 formula Cjall, jKOg is also mentioned, the existence of which 

 speaks clearly for the formula C , gH, gO^ for the original sub- 

 stance, instead of the simple formula C^HjOj. 



Barium- Compound, C^ 3H ^ ^BaOg + H2O. 



If an alcoholic solution of the substance C.^H, ,0^ is added 

 to baryta water, a beautiful roae-colored. precipitate is pro- 



