16O Fossils. 



or acetic, acid. With regard to the pro* 

 portion of oxygen united to acidifiable ra- 

 dicals, still greater latitude may be given 

 to the considerations presented above. 

 Each radical may be contemplated in four 

 states : 1st, containing very little oxygen 

 not sufficient to impart to it the nature of 

 an acid, and in this it is nothing more than 

 an oxyd ; such is sulphur coloured red or 

 brown, by exposure to the air, and a de- 

 gree of heat inadequate to produce infla- 

 mation ; when it is oxyd of sulphur ; 2dly 

 containing more oxygen than in the pre- 

 ceding case, and enough to become an a- 

 cid, though weak ; as in the sulphurous 

 acid ; 3dly, possessing still more oxygen 

 than in the second instance, and having 

 acquired powerful acid properties ; such 

 as the sulphuric acid ; ithly, conjoined 

 with a larger dose of oxygen than is neces- 

 sary to constitute a powerful acid, an acid 

 in ic ; when it is termed an oxygenated 

 acid, or even super-oxygenated. 



The acids are generally divided into 

 mineral, vegetable, and animal, acids, ac- 

 cording to the nature of their radicals. 

 Though the first class only with propriety 

 claims notice in this place, yet for the in- 



