Hypochondriasis seems to be unknown. Canine madness also appears to be without an example, their dogs not having yet been visited by the disease. [239] They are rarely afflicted with dysentery, though children are sometimes subject to it in consequence of eating unripe fruits, such as plums, grapes, and maize. They are never known to be subject to the _coup de soleil_,[9] although they travel for days and even weeks over the unsheltered prairies, without any covering whatever for the head, which is consequently exposed to the full radiance of the sun, both in a state of activity and quiescence. White men residing with them, and who have partaken in their hunts, and consequent insolation, have been visited with this distressing affection, although their heads were protected invariably by hats or handkerchiefs. [9] Sunstroke.—ED. The cuticle of these Indians is not known to have been acted upon by contact with poisonous plants, though white men travelling with them have experienced the effects of the usual deleterious properties of the poison vine (rhus radicans,) which is, to a certainty, abundant in proper situations in the Missouri country. What effects would result from the application of this plant to the only part of the body of the Indian which is never exposed to the direct influence of external causes, is a subject deserving of experimental inquiry. The hare-lip sometimes occurs, but it may be properly considered as still more rare than amongst white people. Frosted limbs are treated by immersion in cold water, so as gradually to restore the lost temperature of the part. The magi also perform over them their mystic rites, amongst which the only topical application is made by chewing some roots and blowing the fragments, and accompanying saliva violently upon the part, with many antic capers. Goiture and wens are not known. Fevers, and fever and ague, are exceedingly rare. Ophthalmic diseases, and casualties affecting the eye, are frequent. The eyes of children are sometimes injured or destroyed by missiles, in incautious play or juvenile {240} rencontres. But blindness is more frequently the effect of the gradual operation of disease. The eyes become sore and the lids inflamed; white opake maculæ, after some time, appear in the eye, which enlarge until they cover it entirely, and prevent the ingress of light. It is probable that they possessed no rational remedy for this evil previously to their acquaintance with the traders, excepting the extracting of blood from the temple by their process of cupping; the traders, however, have taught them to remove the opacity, by blowing burnt alum into the eye through a quill, a remedy so familiar in the veterinary art. To this disease children as well as adults are obnoxious.