ACETIC ACID. 127 



of O5, it is exceedingly probable that the 

 atomic weight of acetic acid is either 6-25 or 6*5, 

 as Berzelius* number lies between these. That 

 I might be able to determine which of these 

 two numbers was the real atomic weight of acetic 

 acid, I dissolved 6-70 grains of anhydrous car- 

 bonate of soda in distilled water, saturated the 

 solution with very pure acetic acid, and evapo- 

 rated the solution to dryness, by means of a gen- 

 tle but long continued heat. The dry salt thus 

 obtained, which was in an eight ounce phial, was 

 kept for four hours upon the sand bath, in a heat 

 which was as nearly as possible 550. I was 

 obliged to repeat this experiment a great many 

 times, before I made myself acquainted with the 

 limit of the temperature which the salt is capable 

 of bearing without decomposition. The heat 

 must be sufficient to keep the salt in a state of 

 fusion, otherwise the whole water is not driven 

 off if it be as high as 600 decomposition takes 

 place. While the salt is in fusion it has a dark- 

 ish colour, but it becomes beautifully white as 

 soon as it congeals, if none of the acid has been 

 destroyed. In two successive experiments, B y the au - 

 which were quite successful, the weight of the 

 salt was 10*25 grains : now, 6'Jo grains of an- 

 hydrous carbonate of soda contain just 4 grains 

 of soda ; consequently, anhydrous acetate of 

 soda is composed of 



