170 



ELEMENTARY BIOLOGY 



thumbs over the small of the back and fingers over the lowest 

 ribs, alternately compresses and releases the chest by swinging 

 forward and back, at the rate of from twelve to fifteen times a 

 minute. The movements should be kept up until natural breath- 

 ing begins, but should not be given up in less than an hour. 



Fig. 59. 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 



While these movements are being carried out, the victim's 

 tongue should be pulled out and kept out, to prevent it from 

 slipping back into the throat and obstructing the windpipe. 



The Silvester method of artificial respiration is shown in 

 Figs. 59 and 60. . 



In case of asphyxiation, or suffocation by gases or by electric 

 shock, the same procedure should be followed, except that it is not 

 then necessary to take special steps for emptying the lungs of water. 



