LXIII.] 



CAPILLARY BLOOD-PRESSURE. 



301 



not synchronous with the blood-heart, whose movements can 

 usually be distinguished without opening the chest. 



(c.) Destroy the posterior part of the spinal cord with a seeker 

 or wire, and observe that the rhythmical automatic movements of 

 the lymph-hearts cease. 



4. Estimation of the Blood-Pressure by Ludwig's Kymograph. 



— As students are not permitted to perform experiments upon live 

 animals, the most they can do in this experiment is to arrange the 

 necessary apparatus as for an experiment, and to make the necessary 

 dissection on a dead animal. 



Fig. 223. — Apparatus 

 used by V, Kries 

 for Estimating the 

 Capillary Blood- 



Piessure. 



FlO. 224.— Posterior Pair of Lymph-Hearts {L) 

 of the Frog. 



A. (//.) Arrange the recording apparatus for a continuous tracing. The 

 clockwork is wound up, and the drum is so adjusted that, when it moves, it 

 unwinds the continuous white paper from a brass bobbin placed near it. 

 Arrange a time-marker connected with a clock, provided with an electric 

 interrupter, to mark seconds at the lower part of the paper. It is usual to 

 use a ])en-writer charged with a solution of aniline (red or blue), to which a 

 little glycerin is added to make it flow freely. 



{b.) Partially fill the manometer with dry clean mercury, and in the open 

 limb of the manometer place the float, provided with a pen or sable brush 

 moistened with aniline ink containing a little glycerin. See that the float 

 rests on the convex surface of the mercury (fig. 225). 



(f. ) The closed or proximal side of the manometer at its upper part is like 

 a T-tube, the stem of Avhich is connected by thick india-rubber tubing to a 

 piece of flexible lead tubing ; on the free end of the latter is tied a glass 

 cannula of considerable size, and over the india-rubber tubing connecting 

 the cannula with the lead tube is placed a clamp. The proximal end of the 



