3 o6 



TEXT-BOOK OF PHYSIOLOGY. 



It has been experimentally demonstrated, however, by Howell 

 and Brush that this interpretation is not correct, but that the greatest 

 oscillation takes place when the external pressure justs equals the 

 pressure in the artery at the end of the cardiac diastole. These ex- 

 perimenters found when the carotid artery of one side was connected 

 with a minimum valve and the carotid artery of the opposite side 

 was surrounded by a plethysmograph in connection with a manometer, 

 that the diastolic pressure indicated by the valve just equaled the 

 lowest point of the greatest oscillation indicated by the manometer 



FIG. 143. ST ANTON'S SPHYGMOMANOMETER. 



the 



-k s Pkpi ol nanorneter, especially adapted for clinical 



use, is that devised by Stanton (Fig. 143 *) 



the^ t ap P ar t tUS u the ?y stolic P ressure ^ determined by noting 



dkstoKc n - PUke reappears after obliteration, while thf 



c pressure is estimated by recording the point at which the 



Pa. Me T dt. f BuS, 



