160 HISTORY OF CHEMISTRY. 



sulphur, form salts with the alkaline and earthy me- 

 tals, rather than sulphurets. The character of these 

 sulpho-salts, however, is still questioned among che- 

 mists; and therefore it does not become us to speak 

 as if their place in history were settled. Of course, 

 it will easily be understood that, in the same man- 

 ner in which the oxygen theory introduced its own 

 proper nomenclature, the overthrow or material 

 transformation of the theory would require a change 

 in the nomenclature; or rather, the anomalies which 

 tended to disturb the theory, would, as they were 

 detected, make the theoretical terms be felt as 

 inappropriate, and would suggest the necessity of a 

 reformation in that respect. But the discussion of 

 this point belongs to a step of the science which is 

 to come before us hereafter. 



It may be observed, that in approaching the 

 limits of this part of our subject, as we are now 

 doing, the doctrine of the combination of acids and 

 bases, of which we formerly traced the rise and pro- 

 gress, is still assumed as a fundamental relation by 

 which other relations are tested. This remark con- 

 nects the stage of chemistry now under our notice 

 with its earliest steps. But in order to point out 

 the chemical bearing of the next subjects of our 

 narrative, we may further observe, that metals, 

 earths, salts, are spoken of as known classes of sub- 

 stances; and in like manner the newly discovered 

 elements, which form the last trophies of chemistry, 

 have been distributed into such classes according to 



