Our system of Anthropology relies, for its demonstration, upon human impressibility. Impressibility in its general sense, or the power of being affected by external agents, is proportional to the development of life. Inorganic matter is affected only mechanically or chemically--vegetation is powerfully affected by causes which would have no perceptible influence on stones or metals, and animals are affected by remote objects, by sounds, by the voice, and by other influences which do not affect vegetables. Animals of a higher grade are affected by many moral influences which produce no effect on the inferior classes, and man, having the fullest development of all, is continually receiving a variety of influences from nature and society, to which animals are wholly insensible. As man is superior to animals in impressibility, so is the man of genius or the man of superior moral sentiments more easily affected by everything that addresses the intellect or the sentiments, than the ignorant and selfish classes of society. Superior impressibility is then the result of a superior development of the organs which feel the various impressions. In the highest order of genius capacities exist which recognize a thousand subtle influences and beauties in Nature of which common minds are unconscious, and the psychic influence of a human being is instantly and thoroughly recognized. For the purpose of analytical experiments upon the human functions, we require the development of a faculty which shall feel the influences we use. We look to the various forms of Sensibility. The organ of physical sensibility is situated in the temples, immediately over the cheek bone. It feels the influences of the various objects which affect the sense of feeling in all its modifications. Heat and cold, moisture and dryness, sound, light, and all the imponderable fluids produce their effects upon this region, and the more it is developed, the more powerfully are we affected by such agencies. The portion of Sensibility which feels the influences of the human nervaura, is the highest portion of the organ, where it connects with Modesty, Somnolence, and Ideality. This we regard as the special organ of Nervauric Impressibility, because it renders the system so sensitive to the nervaura, as to be strongly affected whenever it is applied.