Pure Alcohol placed on the skin evaporates very rapidly, and in so doing abstracts heat, producing a sensation of coolness. This is succeeded by a feeling of warmth in the part; which also becomes red from temporary paralysis of its blood-vessels, causing them to dilate. If the evaporation be prevented, as by putting a little alcohol on the skin and covering it with a thimble, the alcohol acts as an irritant; it causes smarting, and finally sets up inflammation.

On the mucous membranes of the alimentary canal alcohol acts much as on the skin, but its irritant effect is more marked. Placed on the tongue it causes a feeling of coolness, followed by a hot biting sensation, and a red congested condition of the area with which it came in contact. Introduced into the stomach, where it cannot readily evaporate, strong alcohol causes congestion and inflammation varying in intensity with its amount. If the dose is large it sometimes causes death almost instantly, because the powerfully irritated sensory nerves of the gastric mucous membranes reflexly excite a nerve-centre which stops the heart's beat.