508 



APPENDIX 



normal cardiogram as before. Bathe the heart with the solution drop 

 by drop and record the beats just above the normal curve, all conditions 

 else remaining constant. Note the actions of the adrenalin on the pulse- 

 rate and on the power of contraction, and how systole and diastole are 

 each affected. 



Expt. 75. Carbon Dioxide, Oxygen, Ether, Chloroform, Nitrous 

 Oxide, Carbon Monoxide, Ammonia. (Apparatus: Thistle-tube gas- 

 chamber, femur-clamp, heart-lever, kymograph, extra stand-rod, wire, 

 thread, frog's heart, vapors, and bulb for infusing the same.) Arrange 

 the thistle-tube in the femur-clamp directly over the long arm of the 

 heart-lever. Excise the frog's heart, leaving the great vessels long. 

 Pass the wire hook of the gas-chamber stopper through the little mass of 

 the vessels. Pass a thread with a small wire hook on its upper end down 



FIG. 281 



Apparatus as set up by students to show the action of various vapors on the frog's 



heart-muscle. 



through the glass tube and fasten to the long arm of heart-lever near the 

 fulcrum. Insert the wire hook through the ventricle not too near the 

 apex. Place the stopper in position and adjust the fine wire through it 

 so that the beating heart at each shortening will lift the lever. 



By means of the bulb-infuser blow a small amount of a vapor into the 

 gas-chamber and close the openings of the latter. 



Record these drug-cardiograms and compare them with the normal 

 curve. After each experiment thoroughly wash the heart with Ringer's 

 fluid and allow it to rest a short time. 



Expt. 76. Lymph-hearts. (Apparatus: Frog (or tortoise or snake), 

 frog-boards, seeker, watch). Pith the frog's brain and fasten the animal 

 belly-down on the frog-board, the hind legs abducted. By short trans- 

 verse gentle incisions just above the pyramidalis muscle near the end of 



