HYGIENE OF RESPIRATION AND VENTILATION 171 



to the replacement of air by some other gas, or it may be due to 

 the exclusion of air. The replacement of the air in the lungs by 

 water is called drowning. Breathing may also be stopped by a 

 severe electric shock, which acts on a group of nerves that con- 

 trol the breathing movements. Suffocation and drowning are 

 commonly fatal, but in many cases life may be saved by prompt 



Fig. 90. Silvester method of artificial respiration — expanding the chest 



After drawing out the tongue and placing the patient on the back with a block or roll 



under the shoulders, to keep the chest raised and the head thrown back, kneel behind 



the head and grasp the arms just below the elbows. Draw the arms slowly backward 



over the head, and hold them there about one second 



and persistent action. It is necessary (i) to empty the lungs 

 of the water or foreign gas and (2) to reestablish the breathing 

 movements. 



When a person has been drowned, the first thing to do is to 

 place the body, face down, in a position that will cause the 

 water to flow out of the lungs. A child may be lifted by the 

 feet. Breathing movements should be begun at once. 



