142 HUMAN BIOLOGY 



with the proper amount of oil. If this secretion dries, however, 

 and becomes mixed with the loose outer scales of the epidermis, 

 dandruff is caused, and this should be removed by vigorous brushing 

 and shampooing. Not only is the scalp cleaned in both of these ways 

 (if clean brushes and combs are used), but the friction stimulates 

 the circulation of the blood through the scalp, and good blood is a 

 better hair tonic than any external appUcation. If the oil supply is 

 insuflScient and the hair becomes dry, vaseline may be used. The 

 scalp should be well dried after a bath, for moisture at the roots of 

 the hair tends to cause decomposition. Brushes and combs should 

 be kept scrupulously clean. 



205. Care of the nails. — One of the surest means of detecting 

 slovenly personal habits is by watching the care an individual takes 

 of his finger nails. An accumulation of dirt beneath the nails or 

 jagged edges caused by biting the naUs almost always indicate a lack 

 of good breeding. The finger nails should be carefully cleaned with 

 soap, water, and a nail brush or with a nail cleaner, but never with a 

 penknife or scissors, for metal scratches the surface and makes a 

 place for the lodgment of dirt. The roll of epidermis about the base 

 of the nail should frequently be moistened and pushed back ; other- 

 wise this outer skin is likely to become torn and to form the so-called 

 " hangnails." These are often a source of great discomfort and 

 sometimes of danger, for they furnish a possible opening for infec- 

 tion by bacteria. 



206. Treatment of burns. — We have already suggested the 

 treatment for cuts and bruises of the skin in 26. Another form of 

 accident that may injure the skin is a burn. The affected part 

 should be covered and bandaged with a paste of baking soda, which 

 tends to lessen the pain by keeping out the air. A mixture (known 

 as carron oil), half Unseed oil and half limewater, is also a good 

 remedy to keep on hand for burns. If, however, the skin is broken, 

 the wound should be treated with an antiseptic. When the cloth- 

 ing of a person catches fire, the flames should be extinguished by 

 wrapping him quickly in thick clothing or pieces of carpet. 



