VAN SWEITEN, in the article devoted to the consideration of gangrene,[9] has left us a far more exact description of the disease, into which we are inquiring. Practising in a marshy country, he had frequent opportunities of meeting with it; and his account of it, and his mode of treatment, though brief, are every way worthy of the close, practical inquirer into nature, and the sound medical philosopher. His description is not unmixed with strong expressions of horror and commiseration at its ravages. He describes it in a manner so similar to that in which it now prevails, that no doubt can exist of the identity of the diseases. He acknowledges, however, "rubedo, calor, dolor," among its symptoms. Cochlearia, theriaca and similar articles, according to him, are almost always injurious. If no foetor exist, (and, of coarse, no actual mortification,) he applies a solution of sal ammoniac or nitre, with some vinegar or lemon juice; sometimes as a lotion, sometimes by keeping a rag imbued with it always in the ulcer. Hard rubbing he reprobates. If the disease have made progress, and foetor exist, muriatic acid is used: in the less aggravated stages, diluted with honey of roses and water; in the worst cases, pure. This practice he states never to have failed him, unless where the bone was affected. In an early edition of Dr. UNDERWOOD'S Treatise on Diseases of Children, in the library of the Pennsylvania Hospital, no mention is made of this disease; although an article is devoted to "_gangrenous erosion of the cheek_." The account is wholly borrowed from a work by Mr. DEASE, of Dublin, "on the diseases of lying-in women," &c. also in the library. Mr. DEASE describes this affection as occurring from 2 to 6 or 8 years of age; especially in unhealthy children, including such as have been subject to worms. The whole body often appeared cold upon the approach of the disease. A black spot then occurred, but _without marks of inflammation_, on one of the cheeks or lips. The whole cheek was sometimes destroyed, and the lower jaw fell down upon the breast. Muriatic acid, infusion of roses, the effervescing draught, and, in the decline of the disease, bark, broths, jellies, and wine, besides magnesia or rhubarb, to remove the putrid matters swallowed, were the internal remedies employed. The parts were washed and injected with muriatic acid, diluted with chamomile or sage tea; and afterwards dressed with the acid, mixed with honey of roses, and, over this, a carrot poultice. By this practice, Mr. DEASE lays claim to almost total success. In the Philadelphia republication of Dr. UNDERWOOD'S book, taken from the sixth London edition, there is an article entitled Cancrum Oris. The author appears to have read PEARSON'S account; but as his description does not at all agree with the disease of which we are treating, nor with that of Mr. PEARSON, we shall not stop longer to analyse it.