THE importance of ventilating bedrooms is a fact which everybody is vitally interested in, and which few properly appreciate. We copy the following from an exchange, which shows the injurious effects which must arise from ill-ventilated sleeping apartments: "If two persons are to occupy a bedroom during a night, let them step upon weighing scales as they retire, and then again in the morning, and they will find that their actual weight is at least a pound less in the morning. Frequently there will be a loss of two or more pounds, and the average loss throughout the year will be more than one pound. That is, during the night there is a loss of a pound of matter which has gone off from their bodies, partly from the lungs, and partly through the pores of the skin. The escaped material is carbonic acid and decayed animal matter, or poisonous exhalations. This is diffused through the air in part, and in part absorbed by the bedclothes. If a single ounce of wool or cotton be burned in a room, it will so completely saturate the air with smoke that one can hardly breathe, though there can only be one ounce of foreign matter in the air. If an ounce of cotton be burned every half hour during the night, the air will be kept continually saturated with smoke, unless there be an open door or window for it to escape. Now the sixteen ounces of smoke thus formed is far less poisonous than the sixteen ounces of exhalations from the lungs and bodies of the two persons who have lost a pound in weight during the eight hours of sleeping; for, while the dry smoke is mainly taken into the lungs, the damp odors from the body are absorbed both into the lungs and into the pores of the whole body. Need more be said to show the importance of having bedrooms well ventilated, and of thoroughly airing the sheets, coverlets and mattresses in the morning, before packing them up in the form of a neatly-made bed?"