32 



SKETCH OF THE 



schist shall be named siliceo-argillaceous schists. The term primi- 

 tive sandstone, adopted by Dr. Macculloch, I have not made use of, 

 from a similar objection to that stated above regarding the name, flinty 

 slate. I shall simply describe the different varieties of quartz rock as 

 they occur, stating their color, structure, &c. — and under this head, I 

 shall include all those apparently simple rocks, which are principally 

 composed of silica. Small proportions of other ingredients may be as- 

 sociated with this, but the name quartz shall be retained as long as they 

 preserve an apparently homog enous structure. — Quartz rock, as I have before 

 stated, of almost every variety of structure, occurs in this district, asso- 

 ciated with all kinds of rocks, such as micaceous and argillaceous schist, 

 granite, &c. In all these it occurs pure, and is also seen passing into 



them, and acquiring different shades of color from intermixture. This 

 circumstance alone presents a great objection to the division of the rocks 



of this district into submedial and inferior orders. 



Hornstone, is a name applied by Captain Dangerfield* to many of 

 the quartz rocks of this district : — this name might lead us to confound 

 them with the hornstones of the trap formation, with which they have 

 nothing in common. Besides, he has given this name to two rocks of 

 very distinct and different series ; viz. to a rock associated with those of a 

 decidedly old class, and to another, which overlies the sandstones and 



* Since writing the above, I have heard with sincere regret, that this Scientific Officer is no 

 more — and I cannot resist the opportunity of paying my humble tribute of admiration to his me- 

 mory. We cannot be too grateful to him for the light he has thrown on the Geology of Central 

 India, at a time, too, when Geological Science was less understood and less cultivated than at the 

 present day ; and in this expression of my individual feelings I know I shall be joined by all who 

 take the least interest in scientific pursuits. The rough copy of this paper was drawn out before 

 the melancholy intelligence reached me, and I have not deemed it necessary to make any alteration 

 in it, as to substitute the past for the present tense. In a climate like this, how short the space 

 which separates life from the grave. 



