On the fourth day, the rash will appear, but the symptoms will be little, if at all, mitigated; indeed, they will sometimes increase in severity. The eruption will first be perceived about the head and face, in the form of small red spots, at first distinct from each other, but soon coalescing, and forming patches of an irregular crescent-like or semilunar figure, of a dull red colour, and slightly elevated (giving a sensation of hardness to the finger), while portions of the skin intervening between them will retain their natural appearance. At this time the eruption will also be found on the inside of the mouth and throat, and the hoarseness will consequently increase. On the fifth day, the rash usually covers the whole surface of the body, with the exception of the legs and feet; and is now very vivid on the face, which is not unfrequently so much swelled, especially the eyelids, that the eyes are quite closed up, as in small-pox. On the sixth day, it is fully out on the extremities, and is beginning to fade on the face. On the eighth, it is fading from all parts; on the ninth, it is hardly perceptible; and has entirely disappeared on the tenth day from the commencement of the fever, or the sixth from its own first appearance. As the fading proceeds, the spots drop off in the form of little branny scales, which are sometimes, from their minuteness, scarcely perceptible. They leave a slight discolouration on the skin, with considerable itching. Such is the ordinary course of this disease; occasionally, however, deviations are met with. CHARACTER OF MEASLES COMPARED WITH SCARLET FEVER AND SMALL-POX.--Under the description given of Scarlet Fever, are noticed several signs by which that disease may be distinguished from measles: to these may be added the absence of cough, of water flowing from the eyes, and of redness and swelling of the eyelids as in measles. Again, in measles, the eruption is more pointed, of a crimson instead of a scarlet hue, and does not appear until two days later than in scarlet fever. In small-pox, the fever abates as soon as the eruption makes its appearance. In scarlet fever, this is by no means the case; and as little so in measles: the vomiting, indeed, subsides; but the cough, fever, and headach grow more violent; and the difficulty of breathing, weakness of the eyes, and, indeed, all the catarrhal symptoms, remain without any abatement till the eruption has all but completed its course.