Sense of touch —Difference between touch and feeling.— Tactile sensibility and general sensibility.—Organ of touch. Sensation of contact; difference in the sensibility of different regions of the body; simple contact, shock, vibration.—Sensation of pressure; relative aptitude of different regions in appreciating it; variable sensation according to the form of the body and the extent of its surface.—Sensation of temperature, variable according to the temperature of the skin, the density of bodies, and the surface in contact; identical sensation from contact with a body very hot and very cold; relative sensibility of different regions to temperature.— The touch; its delicacy.—The touch compared with the other senses; illusions of touch; persistence of tactile impressions, sensations from internal or subjective causes; causes which modify feeling.