126 Notice of some Recent [Feb. 



Malic Acid, — Liebig recommends ( Poggendorff Ann. 

 xxviii.^) the following process for obtaining this acid. Add 

 carbonate of lime or some other alkaline carbonate to the 

 boiled and filtered juice of the service tree till it is neutral- 

 ized. Mix the neutral solution with nitrate of lead until 

 precipitation ceases, and allow the liquid to remain in a warm 

 place some days. During this time the flocky precipitate 

 is converted into yellowish white needles. Acetate of lead 

 may be employed in place of the nitrate ; but a quantity of 

 colouring matter is thus precipitated. The impure malate 

 of lead is now to be boiled after washing with dilute sul- 

 phuric acid till it loses its granular appearance. To the 

 thick matter, which contains sulphate of lead, sulphuric 

 acid, malic acid, colouring matter, and other acids, a solu- 

 tion of sulphuret of barium is now to be added in small 

 portions. The clear solution will now be filtered, saturated 

 with sulphuret of barium and carbonate of barytes, and 

 heated to the boiling point. Tartrate or citrate of barytes 

 remains undissolved. The pure malic acid is obtained 

 when the barytes is saturated with dilute sulphuric acid. 

 If any barytes should remain in solution, the addition of a 

 little spirit of wine will separate it. 



By analyzing the malate of silver organically he ascer- 

 tained the constituents of malic acid to be 



Carbon 41*47 



Hydrogen .... 3*51 

 Oxygen 55*02 



100-00 

 M. Jules Gay Lussac found in 1832, the composition of 



citric acid, Carbon 42*05 



Hydrogen .... 3*57 

 Oxygen 54*38 



100*00 

 Hence, if these analyses are correct, we have the com- 

 position of each represented by 



4 atoms carbon . . 0*25 

 \ 2 atoms hydrogen . 3 



4 atoms oxygen . . 4 



7*25 

 and their formula is40 + 4C + 2H. 



