WRITINGS OF JAMES SMITIISON. 45 



From tho experiments of Dr. Marcet,* it appears that 

 3.16 grains of muriate of soda, ajQTord 1.7 grains of soda. 



Hence, according to the foregoing experiments, the 10 

 grains of zeolite analysed, consisted of 



Silica ... - 4.90 



Alumina - - - - 2.70 



Soda - . - - - 1.70 



Ice 0.95 ■ 



10.25 

 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 natrolito 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 oblite- 

 rate 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, to those 

 established immemorially by miners and lapidaries, and 

 hence having, with tungstein and nickel, led the vray to the 

 great and brilliant extension which mineralogy 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 imme- 

 diately 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 



* Phil. Trans. 1807. 



