As to the source of infection, the consensus of opinion and ascertained facts point to the sputum as of overwhelming importance; cow’s milk is an important factor; the food may be infected directly by coughing, or the dirt and dust from the floor and hands; the fingers and many other objects that find their way into the child’s mouth are sources of danger. To adults, both dust and moist droplets are more often the source of infection than infected food.

Expectoration.—Careless expectoration is the chief source of infection. Laws should be passed and enforced prohibiting the expectoration on pavements, stairways, in all public conveyances, and all public places.

The danger of infection from tuberculous house servants has not been sufficiently appreciated. A chronic cough in the case of a servant should be at once investigated by the family physician. Servants should be taught the necessity for washing the hands before touching the food or cooking utensils. The condition of their rooms, clothing, bathing, and other personal habits should be closely investigated, and personal cleanliness should be demanded as a sine qua non for obtaining or keeping a situation.

Since it is a well-known fact that tuberculosis can be acquired from the occupation of houses and rooms formerly occupied by tuberculosis patients, it has been suggested that a clean bill of health should be demanded of the owner of the house before renting it; that is, a certificate from the Board of Health, that no case of infection has existed in the house, or that it has been properly disinfected since that time. If such a movement became popular, landlords would be obliged to furnish these bills of health in self-defense. Since the Boards of Health demand the reporting of all cases of tuberculosis, this scheme is by no means impracticable or Utopian.

The tubercle bacillus is not destroyed by any degree of cold, but both light and sunlight are distinctly injurious to these bacteria. The lowest fatal temperature to the tubercle bacillus is 131° F. of moist heat, acting for a period of six hours. The thermal death-point of tubercle bacilli in milk is of great practical importance, and many experiments have been made which have determined that a temperature of from 140° to 167° F., was sufficient if continued for one hour. If it is desired to pasteurize the milk, it should be placed in a closed bottle or stirred and heated for at least twenty minutes at a temperature of 149° F.

Disinfection.—The use of formaldehyd gas has practically displaced the use of sulphur for the fumigation of rooms, as well as for the disinfection of furniture and clothing. For this purpose a moist vapor used in a sealed room is essential.

At least 8 ounces of the commercial 40 per cent. formalin should be used for each 1000 cubic feet of air content. The most efficient method is that used by Biggs, of New York, which is as follows: For an ordinary room, 1000 cubic feet, 1 pound of lime, 8 fluidounces of formalin, and from 2½ to 3 fluidounces of commercial sulphuric acid are required. All openings but the door are sealed. The formalin is poured into an empty water-pitcher, 4 ounces of water are added, and then the sulphuric acid is poured slowly in. The lime is placed in a china or earthenware wash-basin on the floor upon newspapers; all water is removed from the room. All drawers and cupboards opened; the mattresses stood on end; and the mixture poured quickly upon the lime, when the door is sealed. The sulphuric acid may be packed in a tin bucket containing the lime, and, with the formalin in a separate bottle, may be used by any person of ordinary intelligence. The room should remain closed from twelve to eighteen hours. It must not be lost sight of that after disinfection by means of formalin a thorough cleansing is imperative. A room which has been thoroughly cleaned and carbolized is safer than a room which has been disinfected with formalin and not properly cleaned.

After death or removal the entire place should be renovated. Besides disinfection and scrubbing the painted woodwork with a solution of hot soda water, the walls should be repainted or repapered, and the woodwork repainted.

Rugs, bedding, pillows, and clothing should be disinfected by hanging up in the room while it is undergoing disinfection. Books and all articles of small value should be burned. All soiled linen should be boiled.

The Kidneys and their Function.—The kidneys are the secretory organs of the urine; they are two in number, and are the largest tubular glands in the body. They are deeply seated in the lumbar region, lying one on each side of the vertebral column; the kidneys extend from the eleventh rib nearly to the crest of the pelvis. They are usually embedded in a considerable quantity of fat, which is the chief factor in holding them in position, aided to some extent by the large blood-vessels with which they are connected. The kidneys are oblong bodies and measure about 4 inches in length, 2½ inches in breadth, and over 1 inch in thickness. Their weight is about 4½ ounces.

As an excretory organ the kidney probably stands second to the alimentary canal; it surpasses in importance the skin, whose total excretion of water it equals. The abnormal substances appearing in the urine are often not the products of disease of the kidneys, but of some other organ or system.

The kidneys excrete and put the finishing touches upon the urinary fluid; they act at the end of the metabolic course, both as active and as passive agents. While to some extent the kidneys are mechanical contrivances, mere filters, so to speak, they are to a far greater degree active, specific glands. The renal epithelium has the power of synthesis, and builds up complex substances that are not apparent as such in the blood or lymph, as well as the power of analysis or breaking down of substances. These changes are due to the formation in the tubular cell of an enzyme, which we call histozyme. The kidney is the end link in the vascular chain, and the daily performance of healthy kidneys is no doubt a combination of the mechanical and the vital processes.

The Secretion of the Urine.—In a perfectly normal being the problems of waste and repair are balanced to a nicety. As we know, the tissues of the body are bathed in lymph containing in solution the compounds that are necessary for their nourishment—proteids, carbohydrates, fats, salts, and gases. Waste follows in direct proportion to the activity of the tissues. The worn-out, effete material first finds its way into the lymph, and from it into the blood-stream, to be later eliminated from the economy, else deleterious results will follow their retention in the body. It is by the selective action of the cells of the various glands of the body that these useless substances are removed from the blood, and converted into such forms as can be readily excreted. In the main, the products to be removed are urea and the allied nitrogenous bodies—carbon dioxid, salts, and water. These organs are of vital importance, since nearly all of the waste-products containing nitrogen are eliminated in the urine.

The most easily understood function of the kidneys is the excretion of the urinary water; this varies in amount with the rapidity of flow through the renal vessels and to some extent on the blood-pressure.

The separation of the solid substances of the urine form the next function of the kidneys, and these substances fall into two groups—inherently useful materials, which are in excess or which have served their purpose, and substances which are inherently harmful. The latter class embrace many end-products of metabolism, which we are accustomed to consider as normal constituents of the urine.

The analytic study of the urine is of great value to the physician and surgeon, because of the knowledge which it gives concerning the processes of metabolism occurring within the body. The nature and amounts of the various end-products of metabolism are carefully investigated as they occur in the urine, whether they be normal or pathologic.

The Urine.—The normal human urine recently passed is a clear liquid, of a straw color, with an average specific gravity of 1020, the specific gravity indicating the amount of solids contained in the urine. It is acid in reaction. The quantity for twenty-four hours is 50 ounces, or about 3 pints, depending on the amount of water ingested. During sleep the amount secreted is less than at other times. The amount of urine is decreased after profuse sweating, diarrhea, thirst, diminution in the blood-pressure, and after severe hemorrhage. When the body temperature is considerably higher than normal, the amount of urine is again diminished in quantity.

Urea forms nearly one-half of the solids in normal urine and nearly one-half of the urea is nitrogen. It is the principal representative of the waste of the nitrogenous tissues. The chief source of urea is from the metabolism of the muscles; the ingestion of a large amount of proteid food stimulates metabolism. The quantity of urea passed in the twenty-four hours is about 500 grains.

The uric-acid constituent is very small, and in the human urine scarcely reaches 0.03 per cent. of the solids. Lack of exercise leads to an increased formation of uric acid by a lessening of the oxidation of the tissues. In gout the amount of uric acid excreted is abnormally small, because it accumulates in the blood and tissues. The brick-dust deposit sometimes seen in the urine is composed chiefly of the urate of sodium. The average daily amount of uric acid passed in the human urine is about 7 grains. The excretion of uric acid may be increased by drinking copious drafts of water.

Toxicity of the Urine.—After the removal of both kidneys the animal dies of uremia; that is, there is an accumulation of urinary products in the blood. The removal of one kidney is not necessarily fatal, and women have so lived very comfortably for many years. A human being excretes enough poisonous material by the kidneys in two days to cause death.

The Urinary Excretory Apparatus.—After the urine has been secreted by the kidneys it must be carried away from the body, so that the economy may not suffer from the resorption of the contained toxic principles. The excretory apparatus comprises the ureters, the bladder, and the urethra.

The ureters are two cylindric tubes of the diameter of a goose-quill and about 15 inches long. They make their exit from the inner border of the kidney, and pass downward and inward toward the median line, to empty into the base of the bladder by a slit-like orifice.

The bladder is the reservoir for the urine. It is a musculomembranous sac, situated in the pelvis, and in the female it is in front of the uterus and above the vagina. It normally contains one pint. It should be emptied four times a day. If it is allowed to go longer than this, it becomes overdistended, and is apt to displace the uterus backward, and the bladder-walls themselves become weakened.

The Physiology of the Female Generative Organs.—The internal and essential organs of generation are the uterus, ovaries, and the Fallopian tubes. These organs have to do with the process of ovulation, menstruation, and reproduction.

The Ovaries.—These are two small bodies of an almond shape, and lie one on either side of the uterus. The bulk of the organ consists of connective tissue, in which lie embedded the Graafian follicles, or ovisacs, in which the ova are contained.

During the child-bearing period, or from about the age of fifteen to forty-five years, the development of the Graafian follicles and the discharge of the ova are continually taking place. The liberation of the ova usually takes place at definite times, which, in general, coincide with the menstrual epochs, one or more ova being set free at each period, but this is by no means invariable.

The Uterus.—The virgin uterus is a small, hollow, muscular organ, somewhat pear shaped, whose cavity is about 1½ inches deep. The uterus is situated in the middle of the pelvic cavity, between the bladder and the lower bowel. It is held in position by broad elastic bands, which go to different sides of the pelvis; it is also in part supported by the structures below and above it; but so loosely is the uterus held that it is easily pushed about, as, for instance, by a full bladder or a packed bowel, and persistently allowing the bladder to become overful, and failure to have a daily evacuation of the bowels, are prolific sources of displacements of the womb.

Respiratory Movements of the Uterus.—When no constrictions are placed about the waist, the uterus moves freely up and down with every respiration. So distinctly, and with such regularity, do these movements occur that an operator, by watching the movements of the uterus, can tell the effect that the anesthetic is having on the patient’s breathing. These so-called respiratory movements play a very important rôle in the circulation of the uterus, and in the return of the venous blood to the heart.

Anything which interferes with these movements, as the wearing of corsets or of tight bands about the waist, prevents the free return of the venous blood. The uterus becomes congested, and through the constant abnormal weight of the organ itself, as well as by the pressing down upon it from above of the superincumbent organs, the uterus is pushed down below its normal position, the ligaments whose duty it is to hold it up become relaxed, and the unhappy woman suffers all the agonies that are attendant on the “falling of the womb.” For this reason the disorder is frequently met with in women who have never borne children as well as in those who have.

The Functions of the Uterus.—The function of the uterus is to provide a favorable place for the reception of the product of conception, where it may be protected and nourished during the period of its development. The purpose of menstruation is to keep the uterus in suitable condition for the reception of this product of conception at any time. It is now known that the menstrual flow is not the whole of menstruation, and that the changes going on in the uterus are almost as continuous as the process of digestion.

Average Duration of the Menstrual Flow.—The average duration of the menstrual flow is five days, although the variations are considerable in healthy women. A flow lasting any place from two to six days is perfectly consistent with health, but a flow continuing less than two days or more than six days generally indicates a local or general disease.

Character of the Menstrual Flow.—For the first few hours, or perhaps for the first day, the flow is usually slight in quantity and light in color; on the second and third day the flow reaches its height, and is profuse and dark in color, but it should never be clotted; after this it generally ceases. The amount of the flow varies from 5 to 10 ounces. If less than 5 or 6, or more than 18 napkins, are pretty well saturated through, the amount may be considered abnormal.

Premonitory Symptoms of the Flow.—The premonitory symptoms of the monthly flow should not be so marked as to cause the individual any discomfort. The first indication of the return of the period should be the flow. There is generally a feeling of abdominal fulness, with some lassitude and sometimes slight headache. The temperature is lower and the pulse is slower than at other times. This lowered tone of the system is an additional reason for increased care against exposure in wet or cold weather.

Hygiene of Menstruation.—During the menstrual period all cold baths must be strictly prohibited, whether tub-baths or cold sponges. The reason for this is that the application of cold to the surface causes a driving in of the blood from the exterior of the body to the internal organs, and, at the time of the menstrual periods, there is already a congested condition of the pelvic organs, and it must be remembered that congestion is the first stage of inflammation.

Hot or warm sponge baths may be taken throughout the period, and the vulva should be bathed with warm water twice a day throughout the entire period of the flow, as this not only removes the clotted blood before it decomposes and becomes the source of irritation, but also removes other irritating matters, and prevents the nervousness that is caused by local irritation.

Another question which is still sub judice is the necessity for and the frequency with which vaginal douches should be taken; all physicians are agreed that a vaginal douche, taken immediately after the menstrual period, is beneficial, as it removes all of the débris of the flow, which is sometimes very irritating.

Exercise.—A moderate amount of exercise should be taken every day; this is needed now quite as much as at any other time, and only good can result from it, and no harm comes of a woman going out in the rain or the cold weather. As has been shown, the menstrual process is going on for a large part of the time, and the flow is only the external appearance, but during the time of the flow the woman must be unusually careful not to get her feet wet or sit down with damp clothing on. Violent exercise of all kinds is to be prohibited at this time, as dancing, bicycling, gymnastics, and walks of over three miles. The reason for this is very obvious: the uterus has now reached the height of its turgescence, and is heavier than at any other time, hence the danger that displacements or a very profuse flow would be caused by any kind of violent exercise.

Treatment.—If the woman has been so unfortunate as to have been caught out in a heavy rain, so that her clothes have been wet through, or if in the cold weather she should come into the house thoroughly chilled, the best thing to do is to take off her wet things as quickly as possible; be well rubbed down with hot rough towels; drink a cup of hot tea, and go to bed at once, with a hot-water bag placed over the abdomen or under the small of the back. She should remain in bed until the next morning, to the end that the circulation may regain its equilibrium as quickly as possible by the immediate relief of the pelvic congestion.

If this exposure should have caused the sudden cessation of the flow, a hot mustard foot-bath should be taken. One tablespoonful of ground mustard is used to the gallon of water, as hot as it can be borne; the pail should be made as nearly full as possible, without running over, and a blanket wrapped about the pail and woman, so as to cause a profuse perspiration; this should be kept up for ten minutes; as the water cools off, hot water may be added.

Profuse menstruation, painful menstruation, and scanty, very slight, or irregular flow are all abnormal conditions that are due to some abnormal or pathologic causes, and a good gynecologist should be at once consulted, so that not only suffering may be prevented, but that serious consequences to the general health may be averted.