OP ARTS AND SCIENCES. 7 



formed by an alcoholic solution of sodium malonic ester, by sodic car- 

 bonate dissolved in water, or by acid sodic carbonate mixed with very 

 dilute alcohol. The aqueous solution of the salt is, however, entirely 

 decomposed by carbonic dioxide, the original substance being precipi- 

 tated. An aqueous solution of the sodium salt prepared by treating 

 an excess of the original substance with a solution of sodic hydrate 

 gave precipitates with salts of all the common metals except those of 

 the alkalis. Most of these precipitates were red, and among them the 

 following were especially characteristic : — 



Baric, strontic, or calcic chloride, dark brick-red. 



Magnesic sulphate, rust color. 



Zincic acetate, dark chrome-orange. 



Basic plumbic acetate, very dark brick-red. 



The neutral plumbic acetate gave a yellow precipitate, which turned 

 white when in contact with an excess of lead salt. 



Cupric sulphate, dark golden yellow. 



Ammonic hydrate also dissolved the substance with a red color, 

 but the salt was decomposed on trying to evaporate off the excess of 

 ammonia on the water-bath, leaving a whitish residue, which seemed 

 to consist principally of the original substance, with a small amount of 

 decomposition product. The substance is in fact easily decomposed 

 by either ammonic or sodic hydrate, and our rather unsatisfactory ob- 

 servations on these reactions will be found on page 11. The sodium 

 salt boiled under a reverse condenser with ethylbromide in alcoholic 

 solution, passed from red through purple, bluish green, green, and 

 brown to reddish yellow ; sodic bromide was formed, and the other 

 product was an oily substance, which solidified after some time. It 

 will be studied later. The bromine atom in the bromdinitrophenyl- 

 malonic ester seems to be removed with comparative ease. Up to 

 this time, we have studied its behavior in this direction only with 

 aniline (see page 9). 



The Sodium Salt C G IT 2 Br(X0 2 ) 2 CXa(COOC,II,V, 



This substance was prepared by dissolving some of the bromdini- 

 trophenylmalonic ester in alcohol and adding a little sodic hydrate, 

 care being taken that the hydrate was not in excess; a little ether 

 was then added, and the mixture evaporated rapidly in a Bmall beaker 

 sunk throughout its whole length in the water-bath. The ether vapor 

 kept the air from coming in contact with the liquid, while the alcohol 

 was being heated to its boiling point. The residue, after all the alcohol 

 had evaporated, was extracted with benzol to remove the excess of the 



