460 Introduction to the Study of Mineralogy . 



example, should be considered as the basis of a genus, which 

 ihould have as its species the combinations of that earth 

 with the carbonic, phosphoric, and fluoric acids. It is evi- 

 dent that all the parts of a clear and distinct distribution 

 should he symmetrical, and that one method cannot be 

 adapted to two different scales; otherwise it would no longer 

 be a method. 



But if the natural order should prescribe to us to deter- 

 mine the genera according to the most rixed principle of 

 each compound, nothing should hinder us from generalizing 

 under another view the employment of the acids, by bor- 

 rowing from these principles a classical character, serving 

 to connect with each other all the substances not me- 

 tallic of which they form part; and henceforward those 

 6ubstances which bear the name of salts would be united 

 in one and the same superior division with others ; such as 

 the carbonate of lime, phosphate of lime, sulphate of ba- 

 rytes, &c, which had been ranked among the stones. This 

 intimacy had been already as it were prepared for by the 

 transition of the calcareous sulphate from the class of stones 

 into that of the salts. The characters drawn from the solu- 

 bility in water and from the taste, so little remarkable in 

 these substances, had almost obliterated the boundary between 

 the two classes; the definition of salts had become vague 

 and equivocal ; and it appeared to me that it would be to 

 restore order and precision into the class of bodies which 

 had borne this name, to introduce into it all those which 

 contained an acid joined to an earth or an alkali, and some- 

 times to both. The collection of all these bodies will there- 

 fore form the first class, or that of acidiferous substances*. 

 I shall exclude the metallic salts, in order to arrange them 

 among the metals, always taking care not to fritter down 

 the genera. This class will be subdivided into three orders, 

 the first of which will comprehend the earthy-acidiferous 

 substances, the second the alkaline-acidiferous substances, 

 and the third the alkalino-earthy-acidiferous substances. 



* The author uses this word uniformly to express those substances into 

 which acids enter as one of their component parts. We shall -therefore re» 

 tain the term in our translation. — Edit. 



The 



