42 Proceedings of Royal Society of Edinburgh. [sess. 
respiratory movements ; each ‘ rise ’ gives the amount of air 
expired ; inspiration occurs during the ‘ tread ’ of each step ; the 
intervals between the horizontal lines represent 500 c.c. ; the time 
tracing shows a mark every ten seconds. 
The tracings reproduced in figs. 3, 4 and 5 were all taken 
at the same time and from the same individual. The experiment 
begins in each case at the bottom, and is continued until the pen 
has nearly reached the top of the paper. The drum was then 
stopped and the cylinder (and pen) lowered (continuous vertical 
Fig. 4 . — Supine pressure method. 
line), and after a brief interval of natural respiration another 
record of the particular mode of artificial respiration which was 
being investigated was taken. Fig. 3 illustrates the amounts of 
air exchanged in the employment of the Silvester method * 
(forcible raising and subsequently lowering the arms, followed by 
lateral pressure upon the chest); fig. 4, the amount exchanged when 
the Howard method! was used ; and fig. 5, the amount exchanged 
by intermittent pressure over the lower ribs, with the subject 
* H. R. Silvester, The Discovery of tlic Physiological Method of inducing 
Respiration in Cases of apparent Death from Drowning , Chloroform , Still-birth, 
Noxious Gases, etc. etc., 3rd edition, London, 1863. 
t B. Howard, Plain Rules for the Restoration of Persons apparently Dead 
from Drowning, Hew York, 1869. 
