1835.] on Racemic Acid. 163 



V. — RACEMATE OF BARYTE9. 



This salt precipitates in the state of a white powder, when 

 chloride of barium and racemate of ammonia are mixed 

 together in atomic proportions, after having been separately 

 dissolved in water. 



It is a tasteless salt, having a sp. gr. of 2-615. 100 parts 

 of water, at the temperature of 122°, dissolve 0*034 of this 

 salt. It is not sensibly soluble in alcohol. 



When heated it does not melt, but becomes brown, and 

 burns like tinder, giving out a disagreeable fume, which 

 acts on the eyes, and smells exactly like lampic acid. A 

 white carbonate of barytes remains in a state of minute 

 division and very light. 



To determine the composition of this salt it was dried in 

 the temperature of 100° till it ceased to lose weight; 20 grs. 

 were then kept for several hours in a temperature of 320°. 

 The loss of weight was 2*22 grs. When I raised the tem- 

 perature a few degrees higher, the salt began to lose its 

 white colour, when it was in contact with the glass. If we 

 admit that the salt, after being dried at 320°, still retained 

 0'03 grs. of water, its composition will be 



1 atom racemic acid . . 8*25 



1 atom barytes . . . . 9*50 



2 atoms water .... 2*25 



20- 

 Tartrate of Barytes. 



This salt may be formed by a similar process as that which 

 answers for racemate of barytes. It is a white tasteless 

 powder, having a sp. gr. of 2*524. By an indirect experi- 

 ment I conclude that 100 parts of water at 63°, dissolve 

 0*133 parts of this salt. 



When this salt is heated it exhibits the same phenomena 

 as the racemate, excepting that it burns with flame, and 

 that the carbonate of barytes remaining does not cohere, 

 but is in the state of powder, and much heavier than that 

 obtained from racemate of barytes. 



When heated it loses no weight, unless the heat be sufii- 

 ciently high to act upon the acid. It is therefore, anhydrous, 

 and composed of 1 atom tartaric acid . 8*25 



Irod^^) barytes ... 9*5 



M 2 17*75 



