1907-8.] 
The Arterial Pressure in Man. 
343 
XX. —The Arterial Pressure in Man. I. : Methods. By G. A. 
Gibson, M.D., D.Sc., LL.D., F.R.C.P.Ed. 
(Read January 20, 1908.) 
In approaching the consideration of the problems afforded by the arterial 
pressure in man, it is unnecessary to enter deeply into the history of the 
subject. Tigerstedt (1), Hill (2), Vaschide and Lahy (3), and Jane way (4) 
have fully analysed the voluminous literature which has grown up around 
it. It will be sufficient to mention the original experiment of Hales (5), in 
which the arterial pressure was measured by the height to which the blood 
rose in a vertical tube connected with the artery, and of Poisseuille (6), and 
Ludwig (7), who introduced and improved the method of estimating the 
arterial pressure by means of the mercurial manometer, which has since 
been modified by many subsequent observers. To obviate some of the 
disadvantages of the mercurial manometer, which will engage attention at 
a later stage, Chauveau and Marey (8), and Fick (9), almost simultaneously 
introduced elastic or spring manometers. These have undergone many 
alterations at the hands of numerous followers. 
The arterial pressure has been obtained in man by the kymograph on 
a few occasions during operations. Faivre (10) may be referred to as 
having carried out investigations of this sort which must be condemned 
as absolutely unjustifiable. 
The earliest attempt at the clinical estimation of the arterial pressure 
was that of Vierordt (11), who employed for the purpose his own sphygmo- 
graph, weighted in order to ascertain the amount of pressure necessary to 
obliterate the pulsation of the radial artery. Marey (12), Waldenburg (13), 
von Basch (14), Hoorweg (15), Potain (16), Hurthle (17), Bloch (18), 
Mosso(19), Oliver (20), Riva Rocci (21), Hill and Barnard (22), Gartner (23), 
Stanton (24), Cook (25), Erlanger (26), and Janeway (4) have, since his 
time, introduced different forms of clinical sphygmomanometers, which may 
be grouped in respect of their mode of application or with regard to the 
principles involved. 
The sphygmomanometers of von Basch and Potain, as well as the 
earlier instrument devised by Oliver and the smaller instrument suggested 
by Hill and Barnard, estimate the pressure by application directly to the 
radial artery. The three first mentioned register the pressure by means 
of an aneroid, and the other by the resistance of the air compressed in the 
