Page 146. 
84 ON POINTS CONNECTED WITH THE 
First cardio-arterial Second 
Pulse-rate. interval eardio-arterial 
with syspasis subtracted. interval. 
36 ‘00238982’ ‘00239821’ 
49 -00233314’ 00233342’ 
64 002274 00227425’ 
81 *00220541’ -00220546’ 
100 *0021875’ *00218745/ 
121 *002084.55/ *0020847’ 
144 -0020185’ ‘0020185’ 
170 *0019704/ *0019729’ 
After the completion of the cardio-sphygmograph tracing above 
referred to, it was my endeavour to obtain satisfactory double sphyg- 
mograph tracings from arteries at different distances from the heart. 
Two or three unsuccessful attempts suggested the plan which has 
proved successful. It was soon evident that there is only one artery, 
other than the radial, which it is possible to manipulate with any 
degree of facility, especially when the experimenter is the subject of 
experiment. This artery is the posterior tibial at the ankle, where it 
runs in the interval between the internal malleolus and the tuberosity 
of the os calcis, just before it gives off the internal calcaneal branches. 
On myself, this artery is as superficial and as easily reached as the 
radial; in the sitting posture it is quite under command when the 
foot is crossed over the opposite knee; it is considerably further from 
the heart than the radial; and to obtain as great a difference as pos- 
sible, the right wrist was on all occasions the one experimented on, 
the wrist and the ankle being, as far as can be estimated on the 
living body, 29 inches and 523 inches respectively from the aortic 
valves. 
Before going further it will be necessary to consider the sphygmo- 
graph-trace from the posterior tibial artery at the ankle. Wolff* has 
published the results of his observations on the dorsalis pedis artery ; 
and as they correspond with those from the ankle-trace of the pos- 
terior tibial, they may be recapitulated. He remarks that the pulse 
at the foot has a general resemblance to that at the wrist, it differing 
in the primary ascent being less abrupt and the summit less acute. 
In the descent the secondary undulation is remarkably insignificant. 
The other minor undulations are less constant. My observations con- 
firm the above with respect to the general similarity between the two 
pulses, the greater obliquity of the primary rise, and the less constant 
character of the minor undulations; the secondary rise has, however, 
* “ Characteristik des Arterienpuls.” 
