Underneath the Skin
All over the surface of our bodies there are scattered millions of minute orifices, which open into the delicate convoluted tubes lying underneath the Skin, and are called by anatomists sudoriparous glands. Each of these tubes, when straightened, measures about a quarter of an inch; and as, according to Erasmus Wilson, whose figures we follow, there are 3528 of these tubes on every square inch of the palm of the hand, there must be no less than 882 inches of tubing on such a square inch. In some parts of the body the number of tubes is even greater: in most parts it is less. Erasmus Wilson estimates that there are 2800 on every square inch, on the average; and, as the total number of such inches is 2500, we arrive at the astounding result that, spread over the surface of the body, there are not less than twenty-eight miles of tubing, by means of which liquid may be secreted, and given off as vapour in insensible perspiration, or as water in sensible perspiration. In the ordinary circumstances of daily life the amount of fluid which is thus given off from the skin (and lungs) during the twenty-four hours varies from 1⅔ lb. to 5 lb.; under extraordinary circumstances the amount will, of course, rise enormously. Dr. Southwood Smith found that the workmen in the gasworks employed in making up the fires, and other occupations which subjected them to great heat, lost on an average 3 lb. 6 oz. in forty-five minutes; and when working for seventy minutes in an unusually hot place their loss was 5 lb. 2 oz., and 4 lb. 14 oz.—Blackwood’s Magazine.