GEOLOGY OF CENTRAL INDIA. 29 



the strata." I trust I shall be excused if, in describing gneiss which 

 perfectly resembles granite, I shall include it with the granitic rocks. 

 Their constituents are exactly the same, and the distinction does not 

 appear to me very clear or obvious. In as far as this district is concerned, 

 the Wernerian School, at the head of which deservedly stands Jameson, 

 is certainly in the right, and the name and authority of this distinguished 

 Geologist will excuse what might otherwise have been deemed presump- 

 tion in me, in thus stating my opinion in opposition to the authorities 

 before alluded to. 



There are a number of rocks in this district composed of two ingre- 

 dients, generally quartz and felspar. These most frequently are found 

 stratified — to class them with the porphyries, therefore, might lead to con- 

 fusion, and this latter term shall be applied to those only which are not 

 stratified, and which have a distinct porphyritic structure. Indeed this 

 rock, so understood, is of very rare occurrence in this portion of India. — 

 Besides, the rocks under consideration do not resemble the porphyries, on 

 the contrary, they agree in every respect with the granites ; and all things 

 considered, I think it advisable to class them with the granitic rocks — such 

 a classification is in exact accordance with Dr. Macculloch's definition 

 of granite, which definition I have adopted ; and I have only added to his 

 list of constituents " deavlandite,'" which, according to Phillips, is of 

 universal occurrence in rocks of this class. I cannot say that I am pos- 

 sessed of any correct method of distinguishing cleavlandite from felspar. 

 Indeed the only method I know is that of analysis — an analysis which, 

 with my limited apparatus, I find it difficult to conduct — I have frequently, 

 however, observed what I have been in the habit of considering as Uvo 

 distinct varieties of felspar in difierent granitic rocks, and I have no doubt 

 but that one of these is the cleavlandite. 



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