1841.] for the North- Western Provinces. 783 



complete the list of requisites, for the determination of the external 



properties of mineral substances. 

 5. But these physical properties will not in all cases suffice for the iden- 

 Reason for the at- tification, Still less for the determination of the econo- 



tachment ot'a chemi- . . c i j' j • i j 



cal laboratory to the mic value of newly discovered minerals ; and were we 

 rnk'Sog^.^^Ctt to take cognizance of them alone, we would be led, as 

 Western Provinces, j\|ohs has in many instances been, to class together 



and anticipated be- '' ^ 



nefits. substances of the most different nature, on account 



of their external resemblances. Farther, it has been found, that there 

 exists in nature a class of bodies between which the singular quality 

 subsists, of being competent to replace each other in compound mi- 

 nerals without in the slightest degree affecting the external characters 

 of these. Since the class of isomorphous substances is by no means 

 limited in number, the necessity of having recourse to the definitive 

 test of chemical analysis before deciding on the real nature of any 

 mineral presented to us, becomes apparent. The attachment therefore 

 of a small, but effective chemical laboratory, to a Museum of Econo- 

 mic Geology is, I consider, essential to the efficiency of the institution. 

 Such a laboratory ought to be fitted up with special reference to 

 mineral analysis, and as the apparatus and re-agents required for 

 this are not either very extensive or expensive, the necessary outlay 

 would, I believe, be amply compensated by the results of its oper- 

 ation. It is not merely in the department of mineralogy that its 

 aid would be required ; but it will be found, as we advance, that in 

 almost every department of Economic Geology the results of analysis 

 will prove most important, — important not only in an economical, 

 but also in a purely scientific point of view. It is to be remembered 

 that mineralogy is no more limited to the mere identification and classi- 

 fication of minerals than is Astronomy to those of the heavenly bodies, 

 or Botany to those of plants. Like any science it has to do with causes 

 as well as an effect; with laws as well as results, and its true limits 

 will only be attained, when to a clear development of physical pro- 

 perties, it adds the discovery of those principles of internal organisa- 

 tion of which these properties are only the visible exponents. An 

 element of the first importance towards such discoveries, is a thorough 

 acquaintance with the chemical components of mineral substances, so 

 that viewed only as a boon to pure science, the application of analysis 



5 G 



