VI. On the Parasitic Formation of Mineral Species, depending upon Gradual Changes, which take place in the Interior of Minerals, while their External Form remains the same

Extract

Every mineralogist is conversant with some of the facts relative to the subject of this paper. Some of the observations enumerated, are comparatively new, as the attention of naturalists has been only of late more particularly directed towards these facts. Others, which I have had an opportunity of collecting myself, I trust will not be considered uninteresting, as they tend materially to rectify certain ideas connected with the determination of the mineralogical species, the most important branch of natural-historical research.