96 EXPERIMENTAL PHARMACOLOGY 



little salt solution at the same time. The cannula is now 

 tied in and the remaining salt solution is run out through 

 the side tube. The relations of the vein, artery, and nerve 

 are shown in Fig. 90. You will need to knoir these rela- 

 tions well for future operations. 



Now pour into the empty burette about fifteen cubic cen- 

 timeters of adrenaline solution 1-10,000 (Parke, Davis and 

 Co., adrenaline chloride; or synthetic levorotatory adren- 

 aline, Farbwerke-Hoechst Company, New York. The former 

 is advisable). Wash out a little of the solution to get all 

 air out of the tubes. Save the solution washed out and 

 return it to the burette. 



(d) Recording Blood-pressure. Bring the writing point 

 of the manometer (mercury) to the smoked surface of the 

 drum. It is exceedingly desirable for the manometer to 

 carry a signal magnet which marks the base line, or line 

 of zero pressure, and at the same time marks the time 

 intervals as recorded from a master clock, Jaquet chrono- 

 graph, metronome, or other time recording device. The 

 construction of the manometer is shown in Fig. 6. This 

 illustration also shows the method of connecting the man- 

 ometer to the pressure bottle. The best anti-coagulating so- 

 lution to be placed in the pressure bottle for filling the tubes, 

 right limb of the manometer and the cannula, is a solution 

 of sodium citrate (5 to 10 per cent). (Several other salts, 

 Na 2 S0 4 , NaHCOo, MgS0 4 , etc., in varying strengths, are 

 sometimes used.) The signal magnet point should mark 

 about three-fourths of an inch to the left of the manometer 

 pointer. This avoids breaks in the time record in the 

 early part of the tracings. Hold a battery jar under the 

 wash-out tube and open the corresponding clip. Now open 

 the clip at the top of the manometer. The sodium citrate 

 solution will quickly run down and fill the tubes, manometer, 

 and cannula. All air will be washed out. Close the clip 

 on the side tube while the upper clip remains open. In 

 this manner run in citrate solution sufficient to raise the 



