Researches respecting the radical of Benzoic Acid. 283 



and alcohol gave the same result and consequently confirmed the at- 

 om of water of crystallization found in my first analysis. 



I herewith transmit the result of an analysis made in 1813 of sub- 

 limed benzoic acid, which I ignited in a tube with chlorate of potas- 

 sa and chloride of potassium. 



After this method 0-335 gm. of the acid yielded 0-|38gm. water 

 and 0*855 of carbonic acid, which gives in one hundred parts; 



Carbon, 



Hydrogen, 



Oxygen, 



68-85 



4-99 



26-66 



These numbers agree exactly with the composition of the hydra- 

 ted acid C' 4 H 12 O 4 . 



In vain did I endeavor to separate water from the benzoic acid, by- 

 saturating the crystallized acid with a given quantity of oxide of 

 lend, and therefore could not infer the presence of water of crystalli- 

 zation ; this analysis farther gave four atoms of oxygen, although I 

 had previously found by analysis of the salt of lead that the acid in it 

 saturated three limes as much of the oxide as in the neutral benzoate, 

 I was therefore induced since the results did not correspond, to re- 

 ject this analysis of the crystallized acid. 



- I next ignited given quantities of the neutral benzoate of lead, 

 after endeavoring to free the same from water of crystallization 

 by fusion. 



Each analysed quantity of the salt was produced by itself; I have 

 always followed the same principle, because a fault in one single op- 

 eration may become a constant fault in every analysis; I therefore 

 fused each portion of the salt by itself and always obtained varying 

 results; the cause of which difference I believed must be ascribed to 

 to the volatilization of undecotnposed benzoic acid. Upon now 

 comparing the results of these analyses it is evident that different 

 quantities of water still remained in the fused salt. 



In order to prevent the volatilizing of the acid I employed the 

 salt of lead ; this is the analysis 1 have described. The result cal- 

 culated from the corrected atomic weight and compared with your 

 analysis is as follows ; 



Result of the former. Result of the correct analysis. 



Carbon, - - 75-405 - - 74-703 

 Hydrogen, - - 4-951 - - 4*356 



Oxygen, - - 19-644 - - 20-941 



Vol. XXVL— No. 2. 37 



