414 Reflections on some Miner alogical Systems, 



Finally, the physical molecule is considered as without 

 parts : it tan only change ail at once ; therefore in the system 

 of integral molecule, the-re can be no intermediate or demi- 

 species of passage. In the system of" external characters, 

 passages are conceived, and all may he passages, if' it is 

 wished, for it cannot he said why any being is a species. 



in geology things are somewhat different. Granite is 

 composed of' quartz, mica, and feldspar. By withdrawing 

 the influence of mica, if the quantity of" feldspar begins to 

 diminish in the granite, the latter will change its appearance 

 until that by continual variation it becomes gneiss ; and ul- 

 timate'y, when there will be no more feldspar, we shall have 

 micaceous schist. This micaceous schist may lose its quartz 

 or its mica, until it becomes on the one side mica and the 

 other pure quartz. We can therefore suppose all these mi- 

 nerals proceeding from granite, as a common centre, to 

 pure quartz, feldspar and mica, by three or more divergen- 

 cies like passages. But for what ? It is that in them all, 

 we have only the limits which are rigorous or definite, 



In this pretended chain, with the aid of which theorists 

 have so often sought to bind all parts of the universe, we 

 see breaks at every step, and, far irom possessing the whole, 

 we have yet scarcely a few links. It was wished to force 

 them to unite, but the feeble clasps that men have substi- 

 tuted break in defiance of them. 



A celebrated analyst has applied this word passage to a 

 remarkable error. In making experiments on a new sub- 

 stance, he observed that it changed colour under circum- 

 stances which produced the same effect on metallic oxides, 

 while that its other properties tended to those of the earths. 

 Hence he concluded that it constituted the passage or trans- 

 ition from earths to metals. 



I have sucn in Germany, in a beautiful cabinet of petrifi- 

 cations, the head of a bear perfectly preserved and petrified. 



these lovely transition rocks, like all other beautiful things are not numerous, 

 and Mr. Jameson knows only," 1st, transition-limestone ; '2d, transition- 

 trap; :ki, grey-wacke ; and 4th, flinty slate." He adds, in the true style of 

 German logic, p. 145, of what he calls " Elements of Geognosy,"' that 

 *' transition •limestone', which appears to be the oldest member of the transi* 



•■>■;, is a simple rock !" The idea of transition and of tiinpHcrty is v/on- 

 deituily philosophical and congruous, ft wiii prepare the mind of the che- 

 mist foJ , namely, that this simple rock contains petrifications 

 of mar, . sa coraliiies, encrinites, trochites, &c, and that it is " very 

 frequently traversed by small veins of calcspar ; it is not particularly metal- 



;," but that " we possess very little satisfactory information respect- 

 ing either the kind, repository, or quantity of ore it contains;" yet the au- 

 thor hesitates not to declare that it Is both a simple and a ironsiiion (i. e. com- 

 pouodj rock! — TlAffff. 



I in- 



