BOX WINDOW TENT. The box variety of window tent consists of a light steel frame covered with canvas or cloth. The frame fits between the window casing like a wire screen frame. The bottom, through which the head is passed, can be made of flannel and can be drawn closely around the neck. AERARIUM. Dr. Bull's aerarium[3] is another device similar to a window tent. This arrangement consists of a double awning supported on a wooden or steel frame and attached to the outside of the window with a special ventilating arrangement. The head of a cot bed is put through the window and the patient's head rests out of doors. The lower window sash must be raised about two feet and a heavy cloth or curtain hung from its lower edge so that it will drop across the body and shut off the room from the outside air. Window tents have a few advantages. The patient's prolonged rest in bed will be more endurable when he is permitted to look out on the street and watch life than when obliged to gaze at the four walls of his room. Also patients, who can be persuaded only with difficulty to sleep with the window wide open, will not hesitate when they have this tent as an inducement. Draft which the patient usually dreads, particularly in cold weather and when he perspires, need not be feared when sleeping in a window tent. Further, this limits the possible infection to the interior of the window tent, which is obviously an advantage. While, as a matter of course, the patient will have been taught to always hold his napkin before his mouth when he coughs or sneezes, this is not always done, and cannot be done when coughing in sleep. The constant exposure to air and light of the bacilli, which may have been expelled with the saliva and remain adhered to the canvas, will soon destroy them. Also the canvas of the tent is attached to the frame by simple bands and its removal from the frame for thorough cleansing, washing and disinfection is thus made easy. Tents Tents are frequently used for open air living. However, they are not to be recommended for those who can afford to construct open buildings of more durable material. Ordinary tents hold odors. They are often very hard to ventilate; for a strong draft is produced when the flaps are open. There is no ventilation through the canvas, as it is impenetrable by currents of air. In order to make a tent comfortable for a sick person it should have a large fly forming a double roof with an air space between, a wide awning in front where the patient can sit during the day, a board floor laid at least a few inches above the ground, and the sides boarded up two or three feet from the floor. Many modifications of the ordinary tent have been made for the purpose of obtaining a well ventilated canvas shelter.