use_.

Ample provision should be made for fresh air in sleeping rooms, and here
again drafts must be avoided. Especially should the bed be so placed that
strong air currents do not pass over the sleeper. In schoolhouses and
halls for public gatherings the means for efficient ventilation should, if
possible, be provided in the general plan of construction and method of
heating.

[Fig. 47]

Fig. 47--*Artificial respiration* as a laboratory experiment. Expiration.
Prone-posture method of Schaffer.

*Artificial Respiration.*--When natural breathing is temporarily suspended,
as in partial drowning, or when one has been overcome by breathing some
poisonous gas, the saving of life often depends upon the prompt
application of artificial respiration. This is accomplished by alternately
compressing and enlarging the thorax by means of variable pressure on the
outside, imitating the natural process as nearly as possible. Following is
the method proposed by Professor E.A. Schaffer of England, and called by
him "the _prone-posture_ method of artificial respiration":

The patient is laid face downward with an arm bent under the head, and
_intermittent_ pressure applied vertically over the shortest ribs. The
pressure drives the air from the lungs, both by compressing the lower
portions of the chest and by forcing the abdominal contents against the
diaphragm, while the elastic reaction of the parts causes fresh air to
enter (Figs. 47 and 48). "The operator kneels or squats by the side of, or
across the patient, places his hands over the lowest ribs and swings his
body backward and forward so as to allow his weight to fall vertically on
the wrists and then to be removed; in this way hardly any muscular
exertion is required.... The pressure is applied gradually and slowly,
occupying some three seconds; it is then withdrawn during two seconds and
again applied; and so on some twelve times per minute."(39)

[Fig. 48]

Fig. 48--Artificial respiration. Inspiration.

The special advantages of the prone-posture method over others that have
been employed are: I. It may be applied by a single individual and fora
long period of time without exhaustion. 2. It allows the mucus and water
(in case of drowning) to run out of the mouth, and causes the tongue to
fall forward so as not to obstruct the passageway. 3. It brings a
sufficient a