A brain of the proper temperament has its vital energies and excretions moderate, and is not liable to be affected by any externals. Such persons, when infants, have the hair of their head somewhat tawny—when boys, yellowish—and when adults, a bright yellow; being also intermediate between the curly and the straight, and they do not readily fall out. When the temperament is hotter than moderate, all the parts about the head are hotter and redder, the veins in their eyes are perceptible, their hair is grown at birth; and if much hotter, it is black, strong, and curly; but if not much, it is yellowish at first, and then grows black, and in more advanced life such persons become bald; their excretions are small when they enjoy good health; their head becomes filled and oppressed by heating food, drink, and odours, or by any external casualties. Such temperaments are satisfied with little sleep, and even that is generally not profound. The following are the marks of a brain which is colder than proper: The excretions are excessive; the hairs are straight, yellow, and durable; and it is hurt readily by cold things. Such persons are constantly seized with catarrhs and defluxions, the veins of their eyes are not visible, and they are much given to drowsiness. The following are the marks of a brain which is drier than natural: In the excretions nothing redundant, the senses acute, not being given to drowsiness, the hair strong and soon formed, rather curly, and soon falling out. In the more humid temperament, the hairs are straight, do not readily drop out; the senses are muddy, and the excretions redundant, sleep long and profound. In the compound of the hot and dry, the excretions of the head are small, the senses acute, there is a disposition to watchfulness, and baldness. Their hair at first is formed quickly and abundantly, is of a black colour, hot to the touch, and they are ruddy until manhood. But if moisture be joined to heat, and they are not immoderate, the colour and heat are good, and the veins of the eyes large. The excretions are plenteous and moderately concocted. The hair is straight and yellowish, and does not readily drop out. The head is easily filled and oppressed by heating and moistening things. But should an increase of humidity and heat take place, the head becomes diseased, and easily affected by heating and diluent things. Such persons cannot endure long watchfulness, but their sleep is disturbed by fantastical dreams, their sight is dim, and their senses not distinct. The cold and dry temperaments of the brain conjoined together render the head cold and pale, the veins of their eyes do not appear, and they are readily hurt by cold things: wherefore, their health is precarious. Their senses in youth are distinct and faultless, but as they advance in life soon decay. In a word, as far as regards the head, they experience a premature old age; their hair after birth is of slow growth, stunted, and tawny. The