Unscrupulous newspaper advertisements alarm people through incorrect statements about trouble with the kidneys. For example, they declare that a sediment in the urine is a sign of disease; but that is false. The mere act of cooling sometimes causes substances to crystallize out of perfectly normal urine. Or, putrefactive changes which frequently take place after the urine has stood for a time may cause some of its normal constituents to be precipitated. A sediment, either white, pink, or yellow, may indicate that the urine is too concentrated, and consequently means that the individual should drink water more freely; but it generally means nothing more serious. The really important abnormal constituents of the urine, namely, albumin and sugar, never form a sediment.

"Pain in the back" is a complaint frequently used to defraud the public. This symptom does not indicate Bright's disease. It is generally due to the muscles far away from the kidneys, with which, usually, the pain has nothing whatever to do. Similarly a desire to pass the urine frequently does not indicate any disturbance of kidney function, but is explained by the pressure of the enlarged womb against the bladder; it is a very annoying, yet a natural, result of pregnancy.

THE SKIN.—The functions of the skin are at the very foundation of health. It protects the delicate structures which it covers, assists in the regulation of the temperature of the body, and excretes waste products. The excretory function of the skin is always active, but we are unconscious of this activity except on warm days and at times when we perspire freely. In the coldest weather, however, the body throws off what physiologists call the "insensible perspiration." The most important measures for the care of the skin are those intended to insure the activity of the sweat glands, namely, bathing and proper clothing. But before considering these measures, we will describe certain alterations in the skin which cannot escape the notice of the prospective mother, and which she is likely to misinterpret.

On account of the growth of the uterus the abdominal wall is stretched during pregnancy. To a certain degree the skin yields to the distention, but it finally cracks, and lines appear which are commonly called "pregnancy streaks." At first they are delicate and pink or blue in color; later they become white and more extensive.

The streaks indicate the situation of small breaks in the deeper layer of the skin, which is less elastic than the upper layer. They are not painful, and should never cause anxiety. Their size and number vary with the degree of abdominal distention, which in turn depends upon various factors, such as the size of the child and the quantity of amniotic fluid. Although these streaks are most frequently located upon the lower part of the abdomen, they may extend to the outer sides of the thighs; and occasionally appear over the breasts, since they too enlarge during pregnancy. Stretching of the skin, of course, is not confined to pregnancy; consequently, the same kind of streaks often appear in people who are growing stout.

Attempts to prevent or limit the pregnancy streaks prove futile. There is a common belief that they may be prevented by the use of vaselin, goose-grease, mutton-fat, or some one of a variety of lotions; but this teaching is not borne out by experience. None of these applications, however, are harmful, and there can be no objection to using them except that they cause needless soiling of the clothing. After the child is born the streaks fade of their own accord, though they rarely disappear entirely.

In certain localities the skin grows darker during pregnancy. We have already referred to the deepening of the color around the nipple as one of the signs of pregnancy; a similar but much less pronounced discoloration occurs about the navel, which also becomes shallow and may begin to pout in the latter months of pregnancy. About this time, with very few exceptions, there appears a more or less intense brown line which runs downward from the navel in the middle of the abdomen. Sometimes, though not very often, small dark areas, which have been called "liver spots," appear elsewhere over the body. The name is unfortunate, for the spots do not indicate a disorder of the liver.

At present it is generally admitted that alterations in the color of the skin during pregnancy are due to deposits of iron. This mineral substance, among others, as we have learned, is required for the development of the embryo. The child is born with a supply of iron calculated to meet its needs for about a year. Such a reserve is necessary, as Bunge has pointed out, because human milk does not contain enough iron to satisfy the infant's requirements. During pregnancy, therefore, the mother's blood transports iron to the placenta, where it can be absorbed into the child's system; and while being thus transported some of it is deposited in the maternal tissues. The deposits are especially frequent, as I have mentioned, in the middle line of the abdomen, on account of the arrangement of the blood vessels there. Deposits elsewhere may depend upon other conditions; but whatever their cause the pigmentation vanishes a short time after the birth.

Alterations in the color of the skin have no effect upon its excretory function, which, indeed, generally becomes more active during pregnancy. According to one estimate, the average person possesses twenty-eight miles of sweat glands. If these figures are not sufficient to demonstrate the importance of the skin as an excretory organ, surely no one will fail to be impressed by the tragic result which in one case followed throwing all the sweat glands out of action. This was brought about in the case of a young boy whose body was covered with gold leaf to provide entertainment at a Parisian festival. The living statue was not exhibited, however, for shortly after the youth was gilded he became ill and died.

In health more than a pint of water is eliminated through the skin every day, and along with it waste products are removed from the body. Exercise, hot drinks, warm weather, and heavy clothing promote the activity of the sweat glands. Under certain circumstances physicians endeavor to relieve the kidneys by stimulating their patients to perspire freely. It should be clear, therefore, that when a prospective mother naturally perspires it is a good indication. Attempts to stop the perspiration are always ill advised; rather should this function be encouraged by keeping the skin in good condition with baths and warm clothing.