GE'OGNOSY, n. [Gr. the earth, and knowledge.] That part of natural history which treats of the structure of the earth. It is the science of the substances which compose the earth or its crust, their structure, position, relative situation, and properties.

[This word originated among the German mineralogists, and is nearly synonymous with geology. But some writers consider geognosy as only a branch of geology; including in the latter, hydrography, geogony, meteorology and even geography.]