to the capillaries having only the diameter of a blood corpuscle, that these vessels become during suppuration sufficiently dilated to admit of rows of pus globules. Thus, during the formation of an ordinary product of inflammation, the capillary vessels are enlarged; and if excited to still further activity, and for a more protracted period, in the nutrition and formation of tumours, the minute vessels will become still more dilated, and filled with other materials than purulent matter. In a melanotic eye, which I lately examined with Mr. Dalrymple, there was a part in which the black matter seemed to be contained within the capillary vessels. The cancerous tumour afterwards presents a stony hardness, is generally of a globular form, and irregular and unequal in its surface. At a still later period it gradually enlarges, in the way already mentioned, remains moveable for some time, but ultimately becomes fixed by the increased extent of its connections. By these circumstances it may, in general, be distinguished from the tumours which, from the first, occupy a wide space, and are firmly fixed by intimate connections with the surrounding parts. When the tumour has once been developed, its progress is slow and steady, being arrested, or made to recede, neither by the efforts of nature nor by the interference of art. Pain is generally complained of in the region of the tumour, and is of a lancinating kind, compared by the patient to the passing of sharp instruments through the part; occasionally, however, there is no pain in the new formation, and little inconvenience is caused by it. When the disease is left to itself ulceration occurs, frequently at an early period; but sometimes only after the tumour has been of long duration. The superimposed integuments appear stretched, change their natural colour, assume a dusky or livid hue, become attenuated, and ultimately give way; the breach of surface not being caused by tension and pressure, but by the parts having assumed an action similar to that of the tumour. The ulcerated point slowly enlarges, a thin ichorous fluid is discharged, the surrounding integuments are of a dusky red, and the margins of the ulcer are thickened, callous, everted. Whilst the destructive action proceeds in a lateral direction, it at the same time advances towards the more deeply-seated parts, the cavity becomes excavated, irregular, and ragged; and the parts seem to be destroyed partly by ulceration and partly by sloughing. The exposed surface seldom aims at reparation; and when it does, the granulations are greyish, hard, warty, and endowed with but little vitality; never investing the whole surface, but protruding from certain points, and presenting somewhat of a fungous character. The thin unhealthy discharge becomes profuse, and exhales a peculiarly fetid odour, highly offensive to the patient and attendants. By these means the ulcerated cavity may attain an enormous size, presenting a most disgusting