20G PROCEEDINGS OP THE AMERICAN ACADEMY 



dizes it, forming paraiodbenzoic acid, which was recognized by its high 

 melting-point. It is freely soluble in aqueous ammonia, but the aunuo- 

 nium salt could not be obtained in the solid state, as evaporation of 

 the solution, whether on the water-bath or in vacuo, at ordinary tem- 

 peratures, decomposed it, leaving the acid, which was recognized by its 

 sparing solubility in cold water and its melting-point of 135". 



Argentic paraiodalphatoluylate, G^HJCH.^COOAg, was made by 

 adding the solution of the acid in ammonia water, from which the 

 excess of ammonia had been driven off by warming on the water-bath, 

 to argentic nitrate : the white curdy precipitate was washed, dried in 

 vacuo, and analyzed. 



0.7065 gr. substance, dissolved in dilute nitric acid and precipitated 

 with hydrochloric acid, gave 0.2701 gr. of argentic chloride. 

 0.1214 gr. substance gave 0.04:75 gr. of argentic chloride. 



Found. 

 Calculated for CgHglO^Ag. I. II. 



Silver 29.27 28.78 29.45 



Properties. A white curdy precipitate resembling argentic chloride, 

 sparingly soluble in boiling water, from which it crystallizes in lustrous 

 plate.s ; readily soluble in dilute nitric acid. The dry salt is only 

 slightly blackened by heat and liirht. 



Baric paraiodalphatoluylate, Ba{ C^H^IGIl, CO 0)^ . H., 0, prepared 

 by neutralizing baric hydrate with a hot aqueous solution of the acid, 

 and evaporating to crystallization, gave the following results on analy- 

 sis : — 



0.5400 gr. substance dried in vacuo lost, when heated to 100°, 

 0.0153 gr., and gave 0.1881 gr. BaSO^. 



Calculated BalCgHglO.J^ ■ H.p. Found. 



Water 2.66 2.83 



Barium 20.23 20.48 



It forms microscopic white needles, easily .soluble in water. 



The calcium salt, made by treating calcic carbonate with a concen- 

 trated aqueous solution of the acid, was also freely soluble in water, 

 and crystallized in slender branching needles. 



The solution of the ammonium salt of the acid obtained by dissolv- 

 ing it in aqueous ammonia, and driving off the excess of ammonia on 

 the water-bath, behaved as follows with various reagents: — 



