132 COMBUSTIBLE ACIDS. 



Berzelius. It is obvious from the analysis of 

 Berzelius, that the weights of the carbon and 

 oxygen in the acid are the same ; consequently, 

 there must be 4 atoms of the former for 3 of the 

 latter. The hydrogen found by Berzelius would 

 indicate 3 atoms of hydrogen instead of 2. This 

 was, no doubt, owing to the introduction of a 

 very small quantity of water from some unknown 

 source an accident against which it is extreme- 

 ly difficult to provide. 



I have not repeated the analysis of acetic acid, 

 considering the result obtained by Berzelius as 

 sufficient (together with the knowledge of the 

 atomic weight) to determine the composition of 

 this acid. The most accurate method of pro- 

 ceeding would be to employ the crystals of 

 acetate of lead, without depriving them of their 

 water of crystallization. This water has been 

 shown to amount to 3 atoms, and it must be al- 

 lowed for in the calculation ; the quantity of 

 salt which should be employed is 23-625 grains, 

 which is equivalent to an integrant particle. 



5 ' Jt lias been lon known that, when dry 

 acetate of soda and sulphuric acid are mixed in 

 the requisite proportions, and distilled in a re- 

 tort, an acetic acid comes over so strong that it 

 crystallizes when cooled down to a low tempera- 

 ture, and remains in crystals as long as the ther- 

 mometer is lower than 50. If we have a con- 

 siderable quantity of the acid in this concentrat- 



