CITRIC ACID. 



Hydrogen . . 3-800 



Carbon . . 41-369 



Oxygen . . 54-831 



100 



Now, if we suppose the constituents to be 



2 atoms hydrogen = 0-25 or 3-44)8 

 4 atoms carbon =3 - 41*379 



4 atoms oxygen =4 - 55-173 



7-25 100-000 



the weight of the atom of the acid will be 

 indicated by the preceding experiments ; while 

 the constituents per cent, agree very nearly in- 

 deed with those given by Berzelius from his ex- 

 periments. 



5. It occurred to me that, as the quantity of 

 water in the crystals of citric acid had been ac- 

 curately determined, the analysis of a given 

 weight of these crystals would give the most sa- 

 tisfactory evidence of the true constituents of 

 this acid. 9*5 grains of the crystals, in the state 

 of a fine powder, were well triturated with 200 

 grains of peroxide of copper, and exposed to a 

 red heat in a copper tube, with all the necessary 

 precautions to collect the whole of the products. 

 The weight of the water retained by the chloride 

 of calcium approached nearly to 4*5 grains ;* 



* The average of my own experiments gave the amount of water from 

 9-5 grains of citric acid crystals only 4-15 grains. It was a comparison of 

 my experiments with those of Berzelius that induced me to state 4-5 grains 

 as the amount of the water. 



16 



