OF ARTS AND SCIENCES. 191 



The result of Schmelz and Beilstein is here calculated for the 

 hydrous salt. They fouud that the salt, when dried at 100°, lost 

 4.15 per cent of water at 200°, and contained then 58.6 per cent of 

 barium. 



From the lead salt we made the free acid by means of hydric sul- 

 phide, and found it very soluble in water or alcohol, less freely in ether. 

 From aqueous solution it crystallized in irregular rhombic plates, 

 occasionally in more compact prismatic forms. After several recrys- 

 tallizations from water, and thorough drying over sulphuric acid, these 

 crystals melted at 131.5-132°. This agrees with the melting point of 

 malonic acid, as given by Heintzel, although it is somewhat lower than 

 that more recently given by Pinner.* A combustion left no doubt of 

 the identity and the purity of the acid. 



0.3849 grm. substance gave 0.4871 grm. CO2 and 0.1395 grm. IlgO. 



Calculated for C.<,Il404. Found. 



C 34.61 34.51 



H 3.85 4.03 



The quantity of baric malonate which we obtained from muco- 

 bromic acid agreed with the results of our experiments upon a smaller 

 scale, and amounted to nearly 50 per cent of the theoretical yield. The 

 mother liquors contained, beside baric bromide, baric formiate, whose 

 presence could readily be established by qualitative tests. 



Although the gaseous product formed by this decomposition with 

 baric hydrate agreed closely in its qualitative reactions with brom- 

 acetylen, it seemed to us advisable to prove its identity a little more 

 rigorously. We therefore passed the gas, diluted with hydrogen, into 

 bromine and water. The crystalline solid which resulted we washed 

 with dilute sodic hydrate, then with water, and finally recrystallized it 

 from alcohol. Thus purified, it formed long, brilliant prisms, which 

 melted at 54°. The melting point of pentabromethan is given by 

 Lennox t as 48°; by Reboul, $ 48-50° ; by Limpricht and Delbriick, § 

 50-52° ; and by Boui-goin, || 56-57°. The j^rismatic angle could 

 readily be determined, and the measurement of several individuals 



* Berichte der deutsch. cliem. Gesellsch., viii. 965. 

 t Lond. R. Soc. Proc, xi. 257; Ann. Chem. u. Pliarm., cxxii. 122. 

 t C. R., liv. 1229; Ann. Chem. u. Pharm., cxxiv. 267; Bull. Soc. Chim., 

 1862, 75. 



§ Ann. Cliem. u. Pharm., clxv. 297. 



II Ann. Chim. Phys. [6], iv. 423; Bull. Soc. Chim. [2], xxiii. 175, 257. 



