Chapter II: THE PERSPIRATORY GLANDS are fine tubes about 1/300 of an inch in

diameter, and a quarter of an inch in length, which run through the cutis, and then coil up in little balls (Fig. 24). They are found in all parts of the body, and in almost incredible numbers. In the palm of the hand, there are about two thousand eight hundred in a single square inch. On the back of the neck and trunk, where they are fewest, there are yet four hundred to the square inch. The total number on the body of an adult is estimated at about two and a half million. If they were laid end to end, they would extend nearly ten miles. [Footnote: The current statement, that they would extend twenty-eight miles, is undoubtedly an exaggeration. Krause estimates the total number at 2,381,248, and the length of each coil, when unraveled, at 1/10 of an inch, which would make the total length much less than even the statement in the text. Seguin states that the proportion of impurities thrown off by the skin and the lungs, is eleven to seven.] The mouths of these glands--"pores," as we commonly call them--may be seen with a pocket lens along the fine ridges which cover the palm of the hand.

THE PERSPIRATION.--From these openings, there constantly passes a vapor, forming what we call the insensible perspiration. Exercise or heat causes it to flow more freely, when it condenses on the surface in drops. The perspiration consists of about ninety-nine parts water, and one part solid matter. The amount varies greatly, but on the average is, for an adult, not far from two pounds per day. Any suppression of this constant drainage will lead to disagreeable and even dangerous results. If it be entirely and permanently checked, death will inevitably ensue. [Footnote: Once, on an occasion of great solemnity at Rome, a child was, it is said, completely covered with gold leaf, closely applied to the skin, so as to represent, according to the idea of that age, the golden glory of an angel or seraph. In a few hours, after contributing to this pageant, the child died; the cause being suffocation, from stopping the exhalation of the skin; although, in the ignorance of the common people of those days, the death was attributed to the anger of the Deity, and looked upon as a circumstance of evil omen.]

THE ABSORBING POWER OF THE SKIN.--We have already described two uses of the skin: (1) Its _protective_, (2) its _exhaling_, and now we come to (3) its _absorbing_ power. This is not so noticeable as the others, and yet it can be illustrated. Persons frequently poison their hands with the common wood ivy. Contagious diseases are taken by touching a patient, or even his clothing, especially if there be a crack in the cuticle. [Footnote: If one is called upon to handle a dead body, it is well, especially if the person has died of a contagious disease, to rub the hand with lard or olive oil. Poisonous matter has been fatally absorbed through the breaking of the cuticle by a hangnail, or a simple scratch. There is a story that Bonaparte, when a lieutenant of artillery, in the heat of battle, seized the rammer and worked the gun of an artilleryman who had fallen. From the wood which the soldier had used, Bonaparte absorbed a poison that gave him a skin disease, by which he was annoyed the remainder of his life.] Painters absorb so much lead through the pores of their hands that they are attacked with colic. [Footnote: Cosmetics, hair dyes, etc., are exceedingly injurious, not only because they tend to fill the pores of the skin, but because they often contain poisonous matters that may be absorbed into the system, especially if they are in a solution.] Snuff and lard are frequently rubbed on the chest of a child suffering with the croup, to produce vomiting. It is said that seamen in want of water drench their clothing in salt spray, when the skin will absorb enough moisture to quench thirst (see Lymphatic System).

By carefully conducted experiments, it has been found that the skin acts in the same way as the lungs (see Respiration) in absorbing oxygen from the air, and giving off carbonic acid to a small but appreciable amount. Indeed, the skin has not inaptly been styled the third lung. Hence, the importance of absolute cleanliness and a frequent ablution of the entire body.