the nerves, over which the nail grows, are more or less injured when it 

 grows in a wrong direction. The pain from the growing of the nails into 

 the quick, is no proof of their being sentient, any more than the growth of 

 corns proves the. sensibility of the epidermis, of which they are but thick- 

 ened parts, become hard and callous by pressure, and which, confined in 

 tight shoes, press painfully on the nerves below. The nail itself may ac- 

 quire a considerable degree of thickness; I have seen that of a great toe 

 nearly half an inch thick. The use of the nails is to support the tips of 

 the fingers, when they are applied to unyielding substances 5 they like- 

 wise concur in improving the mechanism of the touch*. 



CXXXIII. Of the hair on the head and on other fiarts of the body. 

 These parts are treated of, in the present instance, only in consequence 

 of their connexion with the epidermis ; as, far from improving the touch, 

 they interfere with it, or at least render it less delicate. 



The skin, in man, is more bare than that of other animals; it is, like- 

 wise, least covered with insensible parts that might blunt the sense of 

 touch. In almost all mammiferous animals, the whole body is covered 

 with hair, only a small part of the human body has any hair on it, and 

 that in too snrll a quantity, and of too delicate a texture, to interfere 

 with the touch. Some men, however, have a very hairy skin, and I have 

 seen several who, when naked, looked as if covered over with the skin of 

 an animal, so great was the quantity of hair over the whole body, of 

 which no part was bare, but a small portion of the face, the palms of the 

 hands, and the soles of the feet. This extraordinary growth of hair, is, 

 in general, a sure sign of vigour and strength. In childhood there is no 

 hair except on the head, the rest of the body is covered with down. Wo- 

 men have no beard, and there is in them, a smaller quantity of hair in 

 the arm-pits and on the parts of generation, and scarcely any on the limbs 

 and trunk. But as though the matter which should provide for the growth 

 of the hair, were wholly applied to the hairy scalp, it is observed, that 

 their hair is longer and in greater quantity. 



The colour of the hair varies from white to jet black; and, as will be 

 mentioned, in speaking of the temperaments and the varieties of the hu- 

 man species, this difference of colour is a test by which we judge of those 

 varieties. The colour of the hairs enables us to judge of their thickness : 

 Williof, who, with a truly German patience, was at the pains to count 

 how many hairs were contained in the space of a square inch, states, in 

 Ms dissertation on the human hair, that there are five hundred and seventy- 

 two black hairs, six hundred and eight chesnnt, and seven hundred and 

 ninety light coloured, so that the diameter of a hair, which is between 

 the three and seven hundredth part of an inch, is least in light hair, and 



* The toe nails are favourable lo the laying 1 the foot to the surface on which the body 

 is supported ; they, likewise, improve the sense of touch in this part. The use of the 

 feet is not merely to support the \veight of the body, they are also intended to guide us 

 in feeling 1 for the plane on which we are to rest them, to enable us to judge of the solid- 

 ity, of the temperature, and of the inequalities of the ground on which we tread. They, 

 therefore, required rather a delicate sense of touch. The division of the fore part of the 

 foot, into several distinct and separate parts, serves to enable us to stand more firmly, 

 and facilitates the action of walking. 1 have seen several soldiers who lost, from severe 

 cold, the extremities of their feet, in crossing the Alps which separates France from 

 Italy. Those who had lost only their toes, did not walk so steadily, and frequently fell 

 in treading on uneven ground. Those who had lost one half of their feet, were obliged 

 to use crutches. Author's 



