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TRANSACTIONS OF THE 



The author divides the mineral kingdom into three 

 classes. 1st, minerals possessed of regular forms. 

 2d, minerals yielding regular forms only by cleavage ; 

 and 3d. minerals destitute of regular forms, and not 

 producing them by cleavage. The first is called the 

 crystallized, the second, semicrystallized, and the 

 third, the uncrystallized class, — thus, portions of the 

 species Fluor, (and the author might have added nearly 

 all the others,) are found in all of the classes, according 

 as the individuals are crystallized, cleavable, or mas- 

 sive and amorphous. I cannot help thinking such a 

 partition, is something like a division of quadrupeds, 

 in order to find their names, into skulls with com- 

 plete teeth, skulls with half teeth, and skulls without 

 teeth, and of course a viverra or other carnivorous 

 animal, might be placed in the three partitions, of an 

 indivisible thing. 



We must place ourselves in the situation of the student 

 left to his own resources. I suppose him at first well 

 informed in the terminology, and I know not how he 

 should be, not being provided with select specimens ; 

 suppose, afterwards, he obtains a fine granular sulphuret 

 of lead, he tries its hardness and its specific gravity, 

 and he finds it, by referring to the third class, to be 

 Galena : he gets also a cube, and finds by a second in- 

 vestigation, that it belongs to the first class ; and when 

 he gets also a large concretioned galena, which has 

 three cleavages perpendicular to each other, he finds it 

 to belong to the second class, p. 202, which the author 

 has not quoted. Now, can he convince himself, al- 



