and Origin of the Diamond. 247 



considered merely conjectural. Dr. Brewster supposes the 

 diamond to have originated like amber, perhaps from the con- 

 solidation of vegetable matter, and that it gradually acquired 

 its crystalline form by the influence of time, and the slow ac- 

 tion of corpuscular forces. The late Dr. Voysey adverted to 

 this opinion in his account of the diamond mines of Southern 

 India; and on the occasion of publishing an abstract of that 

 paper in his Journal of Science, Dr. Brewster observed that 

 he saw no reason to alter his opinion. Now, as the rock ma- 

 trix of the diamond of Panna appears, in some respects, 

 though not altogether, to resemble that of Banganpilli in 

 Southern India, there would seem to be little chance of any 

 conjecture being useful; still, however, as every opinion re- 

 garding the origin of this fine mineral is as yet theoretical, I 

 will not withhold what occurred to me on this subject, though 

 I again repeat that I offer it with great diffidence. The theory 

 of Sir James Hall on the consolidation of strata frequently 

 recurred to me when examining the sandstone in which the 

 diamond is found: I thought that I could discern much in 

 favour of it, and particularly in the gradual changes of its na- 

 ture from the lower to the upper strata. Now, if the principle 

 of this theory is admitted to be correct, and applicable uni- 

 versally, it follows of course that it must be applied here ; and 

 then it may be questioned, how the diamond was preserved 

 under that degree of heat which must have been necessary to 

 form its matrix the gritstone? In answer to this objection, 

 I suggest that the circumstance of calc spar occurring in trap 

 rocks is somewhat analogous; and if it is admitted that com- 

 pression under the weight of strata and a superincumbent 

 ocean had the effect of resisting the expansion of its carbonic 

 acid, and constraining it to continue in combination with lime, 

 might not the same principle be reasonably enough applied to 

 account for the preservation and detention of the elements of 

 the diamond in the gritstone ? And, again, should it be further 

 shown that crystals, such as those with which we are familiar 

 in nature, may be produced by slow cooling, or other pro- 

 cesses, according to the above theory, may we not look to it 

 also to account for the crystallization of the gem? 



"This conjecture rests upon the truth or fallacy of Sir 

 James Hall's theory, or on a modification of it; and when 

 this theory is considered as the result of long and patient ex- 

 periment, and the high reputation of its author is taken into 

 account, it will require something more than limited observa- 

 tion or ordinary ability to answer its objections; my part, 

 however, is merely the suggestion of a traveller, and I there- 



