Physiography, signifying etymologically a description of Nature, was originally used for that department of geology (q.v.) which deals with the origin of existing surface features - i.e. the science of landscape. In 1869 Professor Huxley "borrowed the title" for a course of lectures on physical geography treated as "the propaedeutic of natural knowledge," as Kant termed it, or as "an introduction to the study of Nature." These were published in 1877, and in the previous year the Science and Art Department substituted Physiography for Physical Geography in their examinations. Their conception of the subject includes the elementary properties of matter and the forces of Nature, or the elements of chemistry and physics; the nature of the earth's crust, or the elements of geology; the leading characteristics of the sea and the atmosphere, or the elements of hydrography and meteorology; the relation of the earth to other heavenly bodies, or mathematical geography (q.v.); the constitution of the sun and other stars as revealed by spectrum analysis; and the evidence as to the nebular hypothesis, or the main conclusions of modern astronomy.