MOVEMENT OF THE BLOOD IN THE ARTERIES. 



337 



The following table presents the results of Volkmami's observations 1 upon, 

 the relative lateral pressure at four points of the circulation in different 



FIG. 140. 



The Mercurial Kymograph : a, Vulcanite rod of floating piston ; 6, tube which communicates with 

 the pressure-bottle; c, tube which communicates with the artery; d, feeding cylinder. 1, first axis, 

 which revolves once in a minute ; 2, second axis, which revolves once in ten seconds ; 3, axis, in a second 

 and a half. The instrument is furnished with other cylinders suitable for the reception of bands of 

 paper, the surface of which can be blackened after they are fixed on to the cylinders, by causing the 

 cylinder to revolve over the flame of a petroleum lamp, though more frequently the tracings are taken 

 with a brush wetted with solution of anilin dye. 



FIG. 141. 





animals, expressed in millimetres, namely, (i) the carotid near its origin, 

 (n) a peripheral branch of the carotid or some other artery, (in) a periph- 

 eral rootlet of a vein, and (iv) a jugular vein: 



IV. 



18 mm. 



"2 1.5 mm. 



9 mm. 



Op. cit ., p. 173. 



