LXXXIV. 



Flf:. 202. The mercurial kymograph, n. Vulcanite rotl of floating piston, b. Tube which communicates 

 with the pressure bottle, c. Tulie which communicates with the artery, d. Feeding cylinder, i. First axis, 

 which revolves once in a minute. 2. Second axis, which revolves once in ten seconds. 3. Third axis, in a 

 second and a half ( 33). The instrument is furnished with other cylinders suitable for the reception of 

 single Kinds of glaztd pa]>er, the surface of which can lie black, ned after they are fixed on to the cylinders, 

 by causing the latter to revolve over the flame of a petroleum lamp. These cylinders can I* fitted on t*. 

 either of the axes i, 2, or 3, and are always need when it is necessary to employ a rapidly-moving surface, 

 as, .</., for tracing the curves of muscular contraction. 



Fl<:. 206. Normal tracing of arterial pressure obtained with the mermrial kymograph (rabbit'. 



