308 Dr. Hagen on Malic Acid, and the Changes 



cooling, acid malate of lime crystallizes out in perfectly colour- 

 less crystals. It must be well washed with cold water, again 

 dissolved in boiling water, and precipitated by acetate of lead. 

 The lead salt is decomposed by sulphuretted hydrogen, and 

 the malic acid obtained pure by evaporation. 



Malic acid forms with bases two neutral salts, one of which 

 becomes anhydrous when dried at 100° C, while the other still 

 retains water at that temperature. It possesses decided 

 bibasic properties, and the hitherto received atomic weight is 

 necessarily doubled. 



The following salts have been examined : — 



Malates of Lime. 



a. Neutral anhydrous Malate of Lime. 



C 8 H 4 O g -h 2 Ca O, or M 2 Ca O. 



This salt is obtained by saturating a solution of malic acid 

 with lime water. It is a crystalline powder, perfectly insoluble 

 in hot and cold water. 



0-489 gramme of this salt gave 0*319 sulphate of lime, or 

 32*188 per cent. lime. This gives for the atomic weight of 

 the salt the number 2212-40. 



Calculated. Found. 



1 equivalent of Malic acid 1461*39 67-24 67'81 



2 equivalents of Lime . . . 712-04 32*76 32-18 



b. Neutral hydrated Malate of Lime. 



M 2 Ca O + 5 aq. 



M 2CaO + 4aq. (100° C.) 

 If acid malate of lime is saturated with potash, soda, or 

 ammonia, and the solution evaporated at a gentle tempera- 

 ture, we obtain instead of a double salt, malate of lime with 5 

 equivalents of water, in hard shining crystals. When heated 

 to 100° C. this salt is converted into a porcellanous mass, and 

 is found to have lost one atom of water. At 150° C. it 

 becomes quite anhydrous. Of the salt in its first state of 

 hydration, 0*422 gramme dried at the temperature of the atmo- 

 sphere, gave 0-2655 sulphate of lime, or 26*113 per cent, lime, 

 which makes the atomic weight of the salt 2725*0, and gives 

 the following composition : — 



Calculated. Found. 



1 eq. Malic Acid 1461-39 53-44 



2 ... Lime . . . 712*04 26*03 26*113 

 5 ... Water. . . 562-40 20*53 



2735*83 100*00 

 Of the salt dried at 100°:— 



