We have seen that the appearance of blood in the stools is not very frequent: that the most extensive ulceration may and commonly does exist without it; still when blood does appear it is generally found in combination with an ulceration which is not only extensive, but which has penetrated deep into the coats of the intestine. But although this be the general fact, yet it must be borne in mind that blood may be poured out in large quantities without the existence of a single ulcer. In this case the blood issues from the capillary vessels of the mucous membrane of the intestine, and when examined after death this membrane is found to be of a dark red colour, and presents the appearance of ecchymosis. IV. CASES IN ILLUSTRATION OF THE MORBID CHANGES WHICH TAKE PLACE WITHIN THE HEAD, THORAX, AND ABDOMEN, IN THE SAME INDIVIDUAL; OR MIXED CASES. CASE XC. MARGARET EADES, æt. 18, dress-maker. Admitted on the 22d day of fever, which attacked with the ordinary symptoms: at present the mind is dull; the sensibility diminished; there is scarcely any sleep; the eyes injected and suffused; the skin hot; the tongue brown and dry; the pulse 120, but there is no pain in any organ. 23d. Insensibility increased to coma; delirium; tongue dry and quite black; gums bleed on the slightest touch; lips and teeth sordid; four stools, dark and offensive; pulse 110. 27th. Coma undiminished; almost constant moaning; scarcely any sleep; three stools of same character; some cough; pulse 124, feeble. 31st. All the symptoms aggravated; extreme prostration; countenance sunk; cough, without expectoration; respiration with mucous rattle; stools in bed: pulse 140, extremely feeble. Died next day. _Head._ Dura mater vascular; arachnoid thickened and opake; substance of brain highly vascular, in every point thickly studded with red points; effusion between the membranes and into the ventricles. _Thorax._ Mucous membrane of bronchi inflamed; substance of lungs partly condensed and partly tuberculated. _Abdomen._ Mucous membrane of ilium inflamed and ulcerated; other viscera healthy. CASE XCI. WILLIAM MIDDLETON, æt. 18, shoemaker. Admitted on the 5th day of scarlet fever, which commenced, in addition to the ordinary symptoms, with exceedingly severe head-ache, which continues undiminished; scarcely any sleep; eyes red and ferrety; tongue white; bowels loose; pulse 120; eruption apparent only on the chest; no soreness of throat nor difficulty of deglutition. 6th. Pain of head nearly gone; more insensible; pulse 126; eruption fading. 8th. Insensibility increased to coma; adnatæ glistening; tongue brown and dry; lips and teeth sordid; four stools. 10th. Coma deeper; great restlessness; no sleep; stools in bed; pulse 120, weaker. 11th. Increasing restlessness; tongue not to be protruded; deglutition difficult; stools and urine in bed; pulse 150, indistinct. 13th. Died.