On the Composition of Zeolite. 63 



As these experiments had been undertaken more for the 

 purpose of ascertaining the nature of the component parts 

 of this zeolite than their proportions, the object of them was 

 considered as accomplished, although perfect accuracy in 

 the latter respect had not been attained, and which, in- 

 deed, the analysis we possess of natrolite by the illustrious 

 chemist of Berlin renders unnecessary. 



I am induced to prefer the name of zeolite for this species 

 of stone, to any other name, from an unwillingness to ob- 

 literate entirely from the nomenclature of mineralogy, while 

 arbitrary names are retained in it, all trace of one of the 

 discoveries of the greatest mineralogist who has yet ap- 

 peared, and which, at the time it was made, was considered 

 as, and was, a very considerable one, being the first addi- 

 tion of an earthy species, made by scientific means, tc those 

 established immemorially by miners and lapidaries, and 

 h^nce having, with tungstein and nickel, led the way to the 

 great and brilliant extension which mineraloay has since 

 received. And of the several substances which, from the 

 state of science in his time, certain common qualities in- 

 duced Baron Cronstedt to associate together under the 

 name of zeolite, it is this which has been most immediately 

 ■understood as such, and whose qualities have been assumed 

 as the characteristic ones of the species. 



Indeed, I think that the name imposed on a substance 

 by the discoverer of it, ou^ht to be held in some degree 

 sacred, and not altered without the most urgent necessity 

 for doing it. It is but a fi, jble and just retabution of re- 

 spect for the service which he has rendered to science. 



Professor Struve, of Lausanne, whose skill in mineralosy 

 is well known, having mentioned to nie, in one of his let- 

 ters, that from some exper; meals of his own he was led to 

 suspect the existence of pho?phcnc acid in several stones, 

 and particularly in the zeolite of Auvergne, I have directed 

 my inquiries to this point, but have not found the phos- 

 phoric, or any other acknowledged mineral acid, in this 

 zeolite. 



Manv persons, from experiencing much diflRculty in com- 

 prehending the combination togeUier of the earths, have 

 been led to suppose the existence of undiscovered acids in 

 stony crystals. If quartz be itself considered as an acid, to 

 which order of bodies its qualities much more nearly assi- 

 milate it than to the earths, their composition becomes 

 readily intelligible. They will then be neutral salts, sili- 

 cates, either simple or compound. Zeolite will be a com- 

 pound salt, a hydrated silicate of alumina and soda, and 

 Vol. 38. No. 159. July 1811. C hence 



