124 On the most proper Means of [Aug. 



which still remain. We cannot always depend upon the infor- 

 mation of dealers in minerals. Interest often induces them to 

 substitute one country for another. Neither can we, in all cases, 

 make out the localities from the specimens which we find in the 

 cabinets of our friends. The rock, and other characteristic 

 marks, are often common to different localities. I may, out of 

 numerous examples which might be chosen, give one from my 

 own collection. It is a specimen of ajinite, from the fountain 

 of La Caille, in the valley of Chamonix, which has been often 

 conceived to have come from Dauphine. It is likewise of 

 importance to make known the different substances which 

 accompany the same mineral. Nothing contributes more to 

 make us acquainted with the country to which a substance 

 belongs, because the same substances very generally associate 

 together. The eye of the traveller accustomed to observe often 

 rectifies errors by seeing substances in their place, and by exa- 

 mining the depots from which cabinet specimens have been 

 taken. 



In reality our greatest specimens are only atoms in comparison 

 with the masses which we are accustomed to observe in nature. 

 The rocks which we collect for our geognostic collections, are of 

 little importance, except when they have been selected on the 

 spots by ourselves or our friends. These fragments serve for the 

 commencement of the study of geognosy in our cabinets, and 

 they bring to our recollection the great revolutions which the 

 globe has undergone. These mountains always fill us with admi- 

 ration of the Almighty, to whose goodness we are indebted for 

 every thing. When false localities are assigned to rocks it almost 

 always produces serious errors respecting the localities of moun- 

 tains. 



It is easy to see that the geognost cannot really promote his 

 science except by travelling. We ought likewise to employ our- 

 selves in such researches as enable us to determine whether any 

 particular substance is new or not. A new name given to a sub- 

 stance often induces people to believe that the substance is new. This 

 error proceeds from the little exactness in the older descriptions, 

 from the small progress that analytical chemistry had made, and 

 from the little attention which celebrated men, such as Buffon 

 and Linnaeus, formerly paid to mineralogy. Substances, in 

 which we have at present found a sufficient number of distinct 

 characters to separate into peculiar species, were formerly con- 

 founded together under the same name. This kind of indication 

 will not only be useful to the historian of mineralogy, but it will 

 present likewise to amateurs the facility of finding rare substances 

 in old collections placed among common species. The ichlhy- 

 ophthalmiie of Andrada, to which Haiiy has given the name of 

 apophyllite, was known not only by the name of zeolite of' Hel- 

 lesta in West Gothland, but likewise under that of zeolite of 

 L'io in Sudermanland. 1 have found very fine specimens of 



