Miscellanies. 385 



acute become regular prismatic by cleavage. Rutile does not there- 

 fore belong to the third class of Professor Shepard, or the uncleava- 

 ble class ; and he might have spared the student the trouble of 

 searching it among seventy two species, sixty four of the 314th 

 page and twelve of the following one, by absolutely excluding the 

 rutile from the list of his third class. The same will be more or 

 less applicable to the minerals of lamellar, columnar if not impal- 

 pable, and large granular composition ; and thus the list of his third 

 indexlike class would be much curtailed, and consequently, the first 

 order of the same class. What a chaotic order, which comprehends 

 all the solid minerals ! Yet with all this tedious labor of the stu- 

 dent, he cannot be finally certain, whether it is rutile or ostranite y if 

 he does not appeal to the rarity of the latter, which is unknown to 

 him. I hear Professor Shepard reply : The color of the ostranite 

 is clove brown, not liver brown, and the fracture and lustre ar& 

 quite different. Indeed ; but these are not natural properties for 

 Professor Shepard. He is therefore at a loss to understand how 

 the large granular, the fine granular or compact, and the crystallized 

 galena are, per se, for the student, toto codo different in their habit, 

 and he very victoriously affirms at the 318th page, that minerals 

 not differing in their natural properties are identical, so that the 

 different lustre, streak, fracture and color of the three galenas are 

 not natural properties. If they are not in the present case to dis- 

 tinguish two species of galena, the common and the compact, why 

 should they in the other distinguish the genus ostranite from the 

 genus rutile ? 



In my logic I do not see that the frequent division of the species 

 is a consequence (page 317) of the necessity of providing means 

 for the determination of imperfect minerals. Mohs himself, though 

 invested with a triple coat of mail from Kant, has never drawn such 

 a conclusion. Professor Shepard must at least confess, that he tri- 

 plicates the number of the species. Well, he makes the hospital, 

 but he made the poor. 



I never talked of any confusion (page 320) to be experienced in 

 the determination of the leucite from the fact that it has a dode- 

 cahedral cleavage ; I only said, that for the student's sake, in the 

 system of Professor Shepard himself, the leucite, which always oc- 

 curs trapezohedral, should have been put in a new order, the trape- 

 zohedron, like the octahedron, the rhombic dodecahedron, together 

 with the analcime, and the garnet, the perfect trapezohedron of 



Vol. XXX.— No. 2. 49 



