1903-4.] Prof. Schafer on Artificial Respiration in Man. 39 
The Relative Efficiency of certain Methods of per- 
forming Artificial Respiration in Man. By E. A. 
Schafer, F.R.S. (With a Plate.) 
(Read December 21, 1903.) 
Preliminary observations upon this subject, which were made 
by the author on behalf of a committee of the Royal Medical and 
Chirurgical Society of London, are published in a report presented 
by the committee and read on May 26th of this year before that 
Society. 
The methods which were then investigated comprised traction 
by the arms with alternate relaxation, with and without chest 
compression ; and pressure upon the chest walls alternating with 
relaxation from removal of the pressure ; the subjects of the 
experiment being for each method placed successively in the 
supine, the prone and the lateral positions (in the last-named case 
one arm only being used for traction). In addition, the method of 
Marshall Hall was similarly tested. In this, the subject is alter- 
nately rolled over from the lateral to the prone position, expiration 
being assisted by pressure upon the back whenever the subject is 
brought to the prone position. 
It was evident from those experiments that it is possible by 
nearly all the methods investigated to obtain an exchange of air 
per respiration as great as that of the tidal air, the sole exception 
being the methods in which traction alone, without alternating 
pressure upon the lower part of the chest, was employed. 
The number of experiments which we were able to make at 
the time was, however, too limited to enable us to draw any 
positive conclusion regarding the relative value of the several 
methods of performing artificial respiration in man which have at 
various times been recommended, although the experiments clearly 
show the very important part which alternating pressure upon the 
