PURE AIR. The air in the sick-room should be kept as pure as possible. That which is so necessary in health, is indispensable in sickness. The importance, therefore, of a perfect and free ventilation of the sick-room cannot be too thoroughly impressed; and yet to properly secure this end, may call forth a considerable amount of ingenuity on the part of the nurse. A window should be open, but the current of air must not be allowed to blow directly upon the patient. One window may be raised from the bottom and another lowered from the top. This will permit the entrance of pure air from without, and the exit of the vitiated air from within. The patient, if sufficiently covered in bed, is not liable to take cold from a proper ventilation of the room. Especially is this true, when the bodily temperature is raised by febrile or inflammatory affections. The _temperature_ of a room is no indication of the _purity_ of the air. It is a prevalent, but mistaken notion, that when a room is cold, the air must be pure. Cold air is as readily contaminated with impurities as warm air, therefore, it is not sufficient that the room be kept cool, but the air should be frequently changed. During convalescence, great care is necessary to protect the patient from taking cold. Air which is admitted into the sick-room should not be contaminated by passing over foul drains, privies, or other sources of infection, since, instead of invigorating, it depresses the physical forces and generates disease. LIGHT is as necessary to health as is pure air. Banish either for any continuous period of time, and serious results follow. The strong, robust man, when deprived of light, soon degenerates into a feeble, sickly being, and finally dies. According to the investigations of the Massachusetts Medical Society, it was found that absence of sunlight, together with moisture, not only favor the development of tubercular consumption, but act as an exciting cause. It is well known that persons living in shaded dwellings often suffer from forms of disease which resist all treatment until proper admission of light is secured. The physician to the Emperor of Russia found upon examination that patients confined in well lighted wards, were four times as liable to recover as were those in poorly lighted rooms. Children reared away from the sunlight are apt to be deformed and idiotic, while those partially deformed have been restored by being admitted to the light.