428 EXPERIMENTAL PHARMACOLOGY 



with strophanthin (five cubic centimeters equal one milli- 

 gram). How does this affect the heart ? Do you get satis- 

 factory records ? If the heart is in a suitable condition 

 other drugs which may be tried are camphor, strychnine, 

 piloearpine, atropine, adonidin, calcium chloride, caffeine, 

 chloroform, apomorphine, nicotine, cocaine, etc. It may 

 be advisable to kill the heart with digitoxin. If this is done 

 watch carefully to see if delirium cordis is produced and if 

 so what chambers are first affected. Also in what part of 

 the cardiac cycle does the heart stop? Does it stop in 

 systole or diastole in the intact animal? What explanation 

 can you offer f What general conclusions can you draw 

 from the experiment ! What part do the coronary arteries 

 and veins play in the experiment ? What are the sinuses of 

 Valsalva ? What is their function .' Will the absence of 

 intraventricular or mtra-auricular pressure in any way in- 

 validate your observations ? 



There are several other methods for studying the action 

 of drugs on the isolated heart, e.g., those of Frank, Martin, 

 Bock, Starling, Heymans and Kochman, etc. (See Heinz: 

 Handbuch der Pathologie mid Pharmakologie, i, 2, pp. 669 

 and 846 et seq.; also Sollmann: A Text-book of Pharmacol- 

 ogy, 2nd edition, 1906, W. B. Saunders Co., pp. 895 and 953.) 



EXPERIMENT CXXXIII. 

 Accnitine. (Frog: General Action.) 



1. Destroy the cerebrum only of a frog, wait for the 

 shock to wear off and then inject one cubic centimeter of 

 aconitine solution (aconitine 'potent/' five cubic centi- 

 meters equal one milligram) into the dorsal lymph sac. 

 Watch the symptoms carefully and see if there is any stimu- 

 lation of the central nervous system. Are the muscles af- 

 fected! What general conclusions can you draw? 



