The bright red colour of the muscular fibres, an apparently stronger power of contraction, and the whiteness, solidity, and weight of the bones, constitute other peculiarities. The eyes have generally very distinct vision. There are few instances of myopes, and blindness is very uncommon. The teeth are white and firm; they rarely complain of odontalgia, and retain their teeth to old age. Both the Fûrians and neighbouring negroes are attentive to preserve them clean, which is done by rubbing them with the small fibrous branches of the tree called _Shaw_. _Natrôn._ Natrôn is much used as a veterinary medicine. As often as the camels, horses, asses, sheep, &c. drink, a large piece of it is put into the trough of water. The natives conceive that it renders them more eager of their food, and thus tends to fatten them. Some camels refuse it, but in general they acquire a preference for that water which is most strongly impregnated. When they refuse it, the natrôn is pulverized, formed into balls, with the flour of maize, and forced down their throats before they drink. For the human race natrôn is used to remove the head-achs, intermittent and remittent fevers, &c. which prevail during the rainy season. Two or three ounces of crude natrôn are dissolved in water, and taken fasting. It operates as a drastic purge, and with some as an emetic. With robust and plethoric habits, there seems to be no inconvenience from the use of it, but I experienced from it an unfavourable rather than beneficial effect. _Tamarinds._ The tamarind, _Thummara Hindi_[51] one of the most useful as well as valuable of the productions of the country, supplies the want of many others. In defect of lemons and other acids, this fruit, mixed with water, constitutes an agreeable and refreshing drink. When dried by beating in a mortar, it is formed into cakes, each of 2 or 300 drams in weight. The decoction of it is a mild cathartic, and also operates as a diaphoretic; and the natives attribute to it superior virtue as an antidote against certain poisons. _Lactation._ Savary remarks, that in Egypt each mother affords nourishment to her own infant, even in compliance with a command of the Prophet, and that this prevents many diseases. No doubt can exist that the milk of the mother, long secreted and reserved for the child, is the proper nourishment at the birth, and by its acrid quality tends to facilitate the evacuation of the fæces, accumulated during the period of gestation, much better than any thing that can be substituted in its room. But when this effect is once produced, in many cases the milk of any other woman may be better than that of the mother; nay, that of the mother may be insalubrious _à principio_; and it is as yet far from being proved, that the milk of the mother is in all cases the best possible milk for the child.