We are disposed to think, that the great prevalence of fever among the nurses and resident medical attendants of fever institutions, and fever wards in general hospitals, which does occasionally occur, is, in no small degree, owing to the particularly great contamination of the atmosphere, which is liable to take place from the peculiarly strong tendency there is in the body of those labouring under fever, especially of the low or typhoid character, to run to putrescence. The body, it is ascertained, so afflicted, is particularly prone to putrefaction, as is sufficiently attested by the presence of black spots upon the surface, sordes upon the teeth and gums, and the general appearance of corruption, often sufficiently manifest. The secretions and excretions are marked at first by a putrid character, and in a short time they are in an active state of putrefaction. In that state, chemical changes take place, gases are evolved, such as nitrogen, hydrogen, carbureted hydrogen, phosphureted hydrogen, singly and combined, forming for instance ammonia, which is a combination of hydrogen and nitrogen: they become mingled with the atmosphere, and impart to it pestiferous qualities. In fever, the body is much more prone to run into the state of putrefaction, than when in health, or even when affected with merely local disease. The whole system is then affected, the whole functions are deranged, the decayed parts of the blood and solids are not removed, nor are they corrected by admixture with new and purer elements obtained from the products of digestion. The correcting influence of exercise is lost, and likewise the assistance it gives to the due performance of the various secretions; and it need not cause surprise that a body so situated, for days and weeks, becomes at length prone to putrefaction. It will perhaps be argued, that the same corruption or contamination of the air is as likely to take place in the surgical wards, where patients are kept having sores, &c. But in those wards, in general, there is not the same amount of tendency to putrefaction. Their health is often excellent, their functions are often not at all deranged, and their bodies, in general, are not more prone to putrefaction than those in health. There are, to be sure, a multitude of sores and the like, but, as long as they are healthy, and the matter is good, there is no risk of their injuring the air, provided they are kept tolerably clean. Healthy matter is a bland and innocent fluid, not more prone to putrefaction than healthy blood. When healthy, matter may be present in an apartment or ward in abundance, without the least injury being felt by those respiring the atmosphere in the room in which it is contained, as the history of surgical hospitals amply proves.