METHODS OF RECORDING ARTERIAL PRESSURE. 79 



and a time -marker. The band of paper is of sufficient width to enable the 

 experimenter to record, simultaneously with the arterial pressure, the venous 

 pressure, the respiratory movements, the intraventricular pressure, or any 

 other phenomena which require investigation. 



FIG. 51. Hiirthle's recording apparatus. 



A convenient form of arrangement of such drums is that of Hering, as 

 modified by Hiirthle, which is shown in the figure ; the two drums are united 

 by a continuous band of smoked paper. 



Several instruments have been contrived for estimating the arterial pressure 



FIG. 52. Hill and Barnard's sphygmometer. 



in man. 1 The one which has been most extensively used is v. Basch's 2 

 sphygmomanometer. This consists of a small capsule ; the cavity of this is 

 connected with a manometer. The floor of the capsule is formed of a rubber 

 membrane, and this is pressed upon the radial artery until the pulse vanishes 



1 See George Oliver, "Pulse Gauging," London, 1895. 



2 Wien. med. Wchnschr., 1883, S. 673 ; Ztschr. f. klin. Med., Berlin, Bd. ii. S. 79 ; Berl. 

 Jclin. Wchnschr., 1887, S. 181. 



