THE SKIN AND THE KIDNEYS 



193 



the ends of the fingers and toes from injury, and to give 

 a support for the fleshy ends. 



261. The Care of the Finger Nails. The finger nails grow 

 out about three times a year. They should be trimmed 

 once a week, leaving them long enough to protect the 

 ends of the fingers. Nails should 

 never be trimmed to the quick. 

 They should not be cleaned with 

 anything harder than a brush or 

 a bit of soft wood. They should 

 not be scraped with a penknife or 

 anything metallic, as it destroys 

 the delicacy of their structure, 

 and gives them an unnatural 

 thickness. 



" Hangnails " are caused by the 

 skin fastening itself to the nail, 

 which, growing outward, drags the 

 skin along with it, stretching it 

 until one end gives way. To pre- 

 vent this, the skin should be loos- 

 ened from the nail once a week, 



not with a knife or scissors, but FIG. 120. Cross-Section of One 

 with something blunt, such as an 

 " orange stick," made for this pur- 

 pose, the small end of a nailbrush, or an ivory paper cutter. 1 



Half of a Human Hair. 

 Magnified about 300 diameters. 



1 An ingrowing toe nail often causes much pain and inconvenience. It is 

 found most commonly on the side of the great toe, although it may occur 

 on any one of the smaller toes. Ill-fitting boots and shoes in which the 

 toes are cramped together usually cause the trouble. 



The toe nails should always be cut off square, at a right angle to the 

 axis of the toe, and should never be pared close and rounded off at the 

 sides parallel with the extremity of the toe. If they are rounded there is 



