Manifestly if this process is so important to a person in health, it must be doubly so to one who is sick. The impurities of a sick room consist largely of organic matter, including in many instances enormous numbers of the disease germs themselves. If we uncover a scarlet fever patient in the direct rays of the sun a cloud of fine dust may be seen to rise from the body, the dust which carries the contagion itself. In an unventilated place this is but slowly scattered or destroyed, and for many days it retains its poisonous qualities. “The effect of rebreathing the air cannot be overestimated,” says Martin W. Curran of Bellevue Hospital, New York City. “We take back into our bodies that which has been just rejected, and the blood thereupon leaves the lungs bearing, not the invigorating oxygen, but gas and waste matter, which, at the best, is disagreeable to the smell, injurious to the health, and may contain the germs of disease.” Fortunately rooms may be ventilated by means of windows in several different ways with little risk of draught. For instance, the lower sash of the window may be raised three or four inches, and a plain bar of wood an inch in thickness, extending the whole breadth of the window, may be put below the window sash, entirely filling the space. By this means the air current enters above, between the two sashes in an indirect line, and it is gradually diffused through the room without a draught. Here is a simpler way of doing the same thing. Take a heavy piece of paper or cloth, about twelve inches wide, and long enough to reach across the window. Tack it tightly at both ends and the lower edge to the frame, and raise the lower sash of the window a few inches. The air entering will be diverted by the cloth. If the air is very cold it must not be admitted at the bottom of the room, but from the top of the window, and should be directed toward the ceiling so as to fall and mix gradually with the warmer air of the room. The influence of the sun’s rays upon the nervous system is very marked. That room is the healthiest to which the sun has freest access. The sick room should be kept looking bright and cheerful, unless the disease be one that requires the eyes to be specially guarded from the light. The eyes are weaker, however, in all sickness, and the bed should be turned so that the patient does not look directly toward the bright light of the open window.