Count de Bournon on BardigUone. 383 



mens from Dumbarton are well known, in which analcime and 

 prehnite are so conjoined, that it is generally impossible to say where 

 one terminates and the other commences ; but it would be endless 

 to adduce all the examples of this kind, with which I am acquainted, 

 and in which assuredly no transition can be suspected. Why should 

 not the specimen of bardiglione, mentioned by the Abbe Haliy, be 

 classed with these ? 



Remarks respecting the term Bardiglione, 



I have applied to this substance the above denomination, which 

 recalls that already appropriated to one of its varieties by the Ita- 

 lians, and which of itself has no other signification ; conformably 

 to my opinion, that every species, to whatever branch of natural 

 history it belongs, should have a peculiar name allotted to it ; a name 

 that, from its nature, ought to be invariable, like the species it is 

 intended to designate ; while explanatory phrases, which are a 

 natural exhibition of the state of the science at the time they are 

 formed, must necessarily follow its course, and change with it. It 

 is true the name oi Anhydrite has already been given to this substance : 

 but the intention of this name is to express the absence of water in 

 its composition ; and as on this account it may agree with a very 

 great number of other mineral substances, which are in the same 

 situation, it becomes therefore a general term, and not a proper 

 name. This will always be the case, while authors endeavour to 

 give mineral substances a significant name; it being sometimes 

 taken from a quality supposed to be perceived for the first time, but 

 soon after shewing itself to be too general to designate one substance 

 in particular ; and being at other times founded on a quality merely 

 peculiar to the individual, or accidental and of which a great number 



