1835.] on Racemic Acid, 171 



Peroxide of iron combines with racemic acid, and forms 

 a red coloured salt, having a harsh and astringent taste, 

 which I did not particularly examine. 



XI. — RACEMATE OF MANGANESE. 



This salt may be obtained by digesting a solution of race- 

 mic acid over carbchiate of manganese. The carbonate 

 gradually assumes the form of a flesh-red powder. After 

 being dried in the open air it was placed for 48 hours in 

 the vacuum of an air pump, over sulphuric acid. 200 grs. 

 thus treated lost only 0*9 grs. 



The salt thus dried, when put into the mouth, is, at first, 

 tasteless, but, at last, it gives a slight impression of sweet- 

 ness. Its sp. gr. is 1*960. 100 water at 55° dissolve 0*048, 

 and at 212° 0*14 of this salt. 



20 grs. of this salt, by exposure for two hours to a heat 

 of 270°, were reduced to 18*06 grs. In another experiment 

 20 grs. heated to 330° were reduced to 17 grs. 



20 grs., by ignition, were reduced to 6*38 grs. of red 

 oxide, equivalent to 5*94 grs. of protoxide. In another 

 experiment, 20 grs. left Q'Q grs. of red oxide, equivalent to 

 6*06 grs. of protoxide. The mean of the two gives 6 grs. 

 of protoxide from 20 grs. of the salt. The constituents, 

 therefore, must be 



Racemic acid . . . . 1 1 or 8*25 = 1 atom 

 Protoxide of manganese . 6 ,, 4*5 = 1 atom 

 Water 3 „ 2*25 = 2 atoms 



20 

 Thus, the constitution is the same as that of tartrate of 

 manganese. But it is less soluble in water. 



When solutions of chloride of manganese and racemate 

 of soda, in the atomic proportions, are mixed together, 

 racemate of manganese precipitates in beautiful crystalline 

 crusts, having a fine, flesh-red colour, but the shape of the 

 crystals could not be recognized. 



XII. RACEMATE OF NICKEL. 



When solutions of sulphate of nickel and racemate of 

 soda, in atomic proportions, are mixed together, a fine 

 light-green powder gradually precipitates, which is race- 

 mate of nickel. 



