undergone by its Salts at High Temperatures. 311 



Calculated. Found. 



1 eq. Malic acid 1461*39 75*147 



1 ... Magnesia 258*35 13-285 13*294 



2 ... Water . . 224*96 11*568 



a. Neutral Salt. 



1944*70 

 Malates of Zinc 



M 2 Z O + 6 aq 



M 2ZO + -(100°C). 



Is prepared by digesting carbonate of zinc with malic acid, 

 at a temperature not above 30° C. Dried at 100° C. it be- 

 comes anhydrous. 



Of this salt, 0*4570 gave 0*2935 sulphate of zinc, or 32*179 

 oxide of zinc, making the atomic weight 3127*8; the calcu- 

 lated one being 3142*77. 



0*695 of the salt dried at 100° C. gave 0*566 sulphate of 

 zinc, or 40*302 oxide of zinc; making the atomic weight 

 2463*6 ; the calculated is 2467*6. 



Acid Malate of Zinc. M. Z O H O + 2 aq. 



Prepared by adding excess of malic acid to the neutral salt. 

 0*190 of this salt gave 0*082 sulphate of zinc, or 21*343 

 per cent, of oxide of zinc ; the atomic weight deduced from 

 which is 2351*7. The composition of the salt is therefore — 



Calculated. Found. 



1 eq. Malic acid . . 1461*4 63*480 



1 ... Oxide of zinc 503*2 21*861 21*343 



3 ... Water .... 337*4 14*659 



2302*0 

 Braconnot analysed this salt with the same results. 

 Basic Malate of Zinc 



If malic acid is long boiled with excess of carbonate of 

 zinc, there falls down a sandy powder ; of this salt dried at 

 100°, 



(1.) 0*3935 gave 0*178, or 44*66 per cent, of oxide of zinc; 

 atomic weight, 2253*3. 



(2.) 0*255 gave 0*224 sulphate of zinc, or 44*015 per cent, 

 of oxide of zinc; atomic weight, 2286*8. 



(1.) 0*474, burnt with oxide of copper, gave 0*1075 water, 

 and 0*329 carbonic acid. 



(2.) 0*5510 gave water 0*1335, and 0*3835 carbonic acid. 

 This salt is therefore composed of 



