and Sheparcts Treatise on Mineralogy. 335 



mineral, and as affording the most simple arrangement ; and then 

 proceed to such as, by the most authentic analyses, appear to 

 consist chiefly of siHca. Those of which alumina forms the 

 greatest proportion succeed, as being the earth next in age and 

 abundance. Magnesia follows ; then such minerals as consist 

 primarily or in part of zirconia or glucina, or lastly of yttria and 

 thorina." Independently of the loose principles of arrangement 

 here laid down, it sounds like the fancies of days long gone by, 

 this making silica the ^^ oldest" mineral, and alumina " next in 



ase 



I" 



The work begins with the species in the following order : — 

 Q^iiartz, opal^ karpholite, alumocalcite, garnet, idocrase, xanthite, 

 Gehlenite, Prehnite, stilbite, Heiilandite, Davyne, Laumonite, 

 zoisite, epidote, &/C. ; a strange commingling of minerals, whether 

 we consider the principles of chemistry or natural history. From 

 quartz and opal, the first transition is to Icarpholite, a hydrous 

 silicate of alumina and manganese ; next to alumocalcite, a variety 

 of opal f then to the complex anhydrous earthy mineral garnet: 

 soon follows Prehnite, stilbite, Heulandite, &c., hydrous species ; 

 and then the wanderers, zoisite and epidote. 



Take another place in the system, where we find the following 

 order, (p. 192, &c.) — Feldspar, ryacolite, petalite, spodumene, 

 Latrobite, agahnatolite, glaucolite, mesotype, Thomsonite, Peris- 

 terite^ leucophajie, mesole, &c. After feldspar and ryacolite we 

 find nothing of the other feldspar minerals, aiiorthite, albite, 

 &c., so ably investigated by Abich ; these occur many pages 

 off : but there follows spodumene, and soon after, the zeolites, me- 

 sotype and Thomsonite; next, Thomson's Peristerite, (nothing 

 but an iridescent feldspar from Perth, U. C. ;) after this, another 

 zeolite, mesole. 



On page 221 and beyond, ElceoUte is followed by Hauyne ; 

 then hydrous atithophyllite, a hydrous mineral near steatite in its 

 characters ; next ajitrim^olite, a zeolite ; Pericline, one of the feld- 

 spars, (which by the way has been shown of late by Gmelin to 

 be identical with albite ;) Labradorite, albite, other feldspar min- 

 erals ; and then the hydrous silicate, analcime. There is still 

 some appearance of system in this arrangement, for these miner- 

 als contain an alkali. Such incongruous connections prove the 

 fallacy of adopting any general principle as an implicit guide in 

 classification. They cannot be looked upon with much compla- 



