In most families will be found one or more members who possess enough seborrheic infection to cause the spread of the disease throughout the rest of the household.

Causes and Treatment of Premature Thinness of the Hair and Baldness.—It has already been stated that 70 per cent. of these cases were caused by seborrheic eczema. Among other causes may be mentioned a progressive tightening of the scalp upon the skull, the scalp having lost the cushion of fat that is under it in early life; insufficient or improper care of the scalp; daily sousing of the head in cold water, combined with improper drying of the hair afterward; sweating of the head; constant mental strain, either on account of intellectual work or worry; wearing stiff, unyielding hats; gout, and all diseases which lower the general nutrition.

The chief treatment is by prophylaxis, or using preventive measures to insure the healthy condition of the scalp. And first and most important of these is cleanliness. Because of the great length of time which it takes to dry long, thick hair, many women do not wash the scalp often enough. In the healthy state of the scalp it should be washed at least once a month.

The Care of the Hair.—There is never any danger of shampooing the healthy scalp too frequently. The oil in the scalp is not removed by washing, but is, on the contrary, always increased through the improvement in the circulation. Where there is much dandruff, or if the hair has begun to fall out prematurely, owing to long neglect or following an illness, it is well to begin by washing the hair two or three times a week, and then gradually increase the interval to every two or three weeks.

Borax in the water cleanses the scalp well, but its continuous use is injurious; the same may be said of ammonia water.

One of the best shampoos is the tincture of green soap. If this cannot be obtained, take of the official green soap 2 ounces, and of alcohol, 1 ounce; mix well, and make shampoo. One ounce of the tincture or its substitute should be diluted with twice as much water and applied to the scalp with the tips of the fingers. When enough of the shampoo has been used, add sufficient water to make a good lather. This must be thoroughly rubbed into the scalp, going over the whole systematically. After the scalp is cleansed, the soap must be well rinsed out of the hair. This may require many changes of the water, but it is most important. Dry the hair with hot towels, the process being completed by a radiator or stove oven. Fanning the hair will hasten the process very considerably. The hair should then be loosely braided and a hot towel wound around the head to insure perfect dryness of the hair and as a prevention against taking cold. One hour is sufficient for the entire procedure. In winter the hair should be washed just before retiring.

Brushing the Hair.—Brushing increases the growth of the hair by stimulating the circulation in the scalp and by removing the dandruff. To be effective, the hair should be well brushed at least once a day, when there must be a deep brushing of the entire scalp. The bristles of the brush must be stiff enough to warm, but not to scratch, the scalp. Brushing and massage remove any loose hairs that are ready to fall, but they will soon be replaced by new vigorous ones.

Combing simply disentangles the hair. The teeth of the comb must be far apart and have rounded ends. In no case should a fine-toothed comb be used. It tears out the hair, and often causes an irritation of the scalp which leads to disease.

From what has been said, it will be seen that every member of the family should have a brush and comb for her own exclusive use, and that no one should allow a public brush or comb to be used on her head.

The brush and comb must be washed once a week in water containing a little ammonia; they must be well rinsed out in pure water; the brush should be dried quickly, with the bristles down. If the brush and comb are not cleaned sufficiently often, the scales of dandruff would be sufficient to reinfect the scalp.