on the scalp with a medicine dropper and thoroughly rubbed in
with the fingers. After three or four hours the hair is washed with soap
and water (any good toilet soap will do) and rinsed with pure water. The
hair is then dried, the surplus water being removed with a coarse towel.
Where the dandruff is very troublesome, this treatment may be given once
or twice a week; but in mild cases once a month is sufficient. Massage of
the scalp, by increasing the circulation at the hair roots, is beneficial,
but irritation by a fine-tooth comb, a stiff hair brush, or by other means
should be avoided. Frequent brushing and combing, however, are necessary
both for the good appearance of the hair and for spreading the oil
secreted by the glands at the hair roots.

*Summary.*--The skin forms the external covering of the body and also
serves additional purposes. It is a most important agency in adapting the
body to its physical surroundings, as shown by the part which it plays in
the regulation of the body temperature. The skin should be kept clean and
active, and skin wounds, even though small, should be guarded against
infection.

*Exercises.*--1. Name an example of each of the protective coverings of the
body.

2. Compare the dermis and the epidermis with reference to thickness,
composition, and function.

3. To what is the color of the skin due? How is the color of the skin
affected by the sunlight?

4. What modifications of the epidermis are found on our bodies? What are
found on the body of a chicken?

5. What different kinds of protection are provided by the skin?

6. How does the perspiration cool the body?

7. What change occurs in the circulation in the skin when the body is
becoming too cold? When becoming too warm? What is the purpose of these
changes?

8. How does alcohol cause one to _feel_ warm when he may be losing too
much of his heat?

9. What precaution should be observed by one in poor health, in taking a
bath?

10. How may the cold bath be a means of improving the general health?

PRACTICAL WORK

*Observations on the Skin and its Appendages.*--Examine the palm of the
hand with a lens. Note the small ridges which correspond to the rows of
papillae beneath the cuticle. In these find small pits, which are the
openings of the sweat glands.

2. Examine the epidermis on the back of the hand and palm. At which place
is it thickest and most resisting? Is it of uniform thickness over the
palm? Try p