138 COMBUSTIBLE ACIDS. 



preceding experiment, being well washed, and 

 dried in the temperature of 212, weighed 11-25 

 grains ; and it was obviously composed of 



Succihic acid 6-25 or 0-555 

 Peroxide of iron 5 - 0-444- 



1-000 



The salt being neutral, and five being the atomic 

 weight of peroxide of iron, 6*25 must be the 

 atomic weight of succinic acid. 



Thus it appears, that acetic and succinic acid 

 have the same atomic weights ; yet scarcely any 

 two acids differ more from each other in their 

 properties. Acetic acid is so soluble in water 

 that it is difficult to obtain it in the state of 

 crystals, and these crystals cannot exist, unless 

 they contain an atom of water united to an atom 

 of acid; but succinic acid requires nearly 100 

 times its weight of water to dissolve it, and its 

 crystals contain no water whatever. There is 

 some analogy, however, in the way in which the 

 two acids combine with bases. Thus, acetic 

 acid unites with 1 atom and with 2 atoms of 

 protoxide of lead, and so does succinic acid. 

 Probably many other similar analogies would be 

 discovered if the succinates were better known 

 than they are at present. 



2. I have not made any experiments upon the 



tion of sue- . , 



id. constituents o| this acid, because 1 considered 



