1836.] Racemic Acid. 249 



maining undissolved, was collected on a filter and washed. 

 When dried on the filter it weighed 15*14 grs. Hence, the 

 racemic acid combined with it must have amounted to 4-56 

 grs. Thus, we have racemated sub-oxide of mercury com- 

 posed of Racemic acid . . . 8*25 



Sub-oxide of mercury 27*39 



The oxide of mercury should have weighed only 26 grs. 

 The excess was owing to the impossibility of drying it suffi- 

 ciently. On making the attempt it was partly converted 

 into running mercury. 



350 grs. of crystallized nitrated sub-oxide of mercury 

 were digested with 127 grs. of racemate of soda, containing 

 82*5 grs of racemic acid. The racemated sub-oxide of mer- 

 cury which precipitated, weighed 332*6 grs. 



The residual liquid being evaporated, left 112 grs. of a 

 light-yellow salt, from which I extracted 4*1 grs. of a yellow 

 matter, consisting chiefly of oxide of mercury, though it 

 was not free from racemic acid. The liquid freed from this 

 matter gave colourless crystals of nitrate of soda, weighing 

 107*53 grs. It is obvious that a loss was sustained amount- 

 ing to rather more than 2 per cent. This loss, doubtless, 

 was owing to some water contained in the 350 grs. of 

 nitrated sub-oxide of mercury. 



XIX. RACEMATE OF SILVER. 



This salt may be formed by mixing together solutions of 

 nitrate of silver and racemate of soda, in atomic proportions. 

 A curdy precipitate falls, which, being washed with cold 

 water, and dried on the filter, constitutes racemate of silver. 



When thus formed it is white, but becomes black, (pro- 

 bably by the partial reduction of the silver) when heated. 

 Its sp. gr. is 3* 168. At the temperature of 100° Fahrenheit, 

 100 parts of water dissolve 0*268 parts of this salt. In 

 consequence of this degree of solubility, small as it is, this 

 racemate is not tasteless, but may be recognized by that 

 peculiar impression which characterizes the salts of silver 

 in general. 



To determine the composition of this salt 107*5 grs. (5 

 atoms) of nitrate of silver were mixed with 61 25 grs. (5 

 atoms) of racemate of soda. The racemate of silver which 

 precipitated weiglied 97*2 grs. when dried on the filter ; 



