Autograph Letter Signed to the English mineralogist and geologist William Phillips (1775-1828).

12mo: 2 pp. Very good. Addressed to 'Mr. W. Phillips' on otherwise-blank second leaf of bifolium, which carries traces of previous mount. Acknowledges 'the obliging present' of Phillips's 'valuable work on mineralogy' (the influential 'Outline of the Geology of England and Wales', 1822, written with William Conybeare). 'I have been for some time anxiously expecting the appearance of this new Edition [an earlier version had appeared in 1818] as I had given my last copy to a friend.' He is 'sorry the authorities are not sufficient to warrant the publication of the list I did myself the pleasure of sending you as an extensive table arranged in the order of specific gravities is I imagine, still a desideratum.'