44 Proceedings of Royal Society of Edinburgh. [sess. 
The following tables will serve to show the results yielded by 
the four principal methods which have been recommended for 
artificial respiration in man. In each case the respirations were 
performed during five minutes, but as the spirometer was only 
graduated to ten litres, it was necessary to take the amount of 
air yielded by each minute separately. In the intervals the 
subject was allowed to breathe naturally. There are also two 
tables (I. and II.) giving the amount of air breathed naturally 
into the spirometer, the circumstances being otherwise similar. 
Fig. O'. — Two middle tracings, natural respiration ; two lateral 
tracings, artificial respiration l>y prone pressure method. 
In the one series of these the subject was supine, in the other 
prone. Since, from the result recorded in these two tables, it 
appeared that the normal rate of respiration was about 13 per 
minute in the subject under the conditions of the experiment, 
this was the rate aimed at in performing artificial respiration. 
The same operator and the same subject took part in all the 
■experiments. The amount of pressure produced by the weight 
of the upper part of the body of the operator when thrown 
forward on to his hands in performing the artificial respirations, 
shown in Tables IY. and VI., was determined to be about 60 lbs. 
The statistics of the subject of experiment are as follows : — 
