AC'TIOX OF DIGITOXIN 407 



striction) may be given and this can be followed by an in- 

 jection of sodium nitrite to determine the action of this 

 body on the bronchial musculature. This is a point of con- 

 siderable clinical interest. How does adrenaline compare 

 with the nitrites as regards its power to dilate the bron- 

 chioles! Would it make any difference whether the bron- 

 choconstriction Avas due to nervous origin (as is the case 

 with pilocarpine) or to a direct muscular stimulation (as 

 occurs with ergamine) ? Which of these conditions exists 

 in clinical bronchial asthma? Stop the artificial respira- 

 tion and kill the animal. 



After the animal is dead open the chest, dissect out the 

 heart and study carefully the position and relations of both 

 auricles and both ventricles. Innate the lungs and see how 

 much these would be in the way in taking myocardiograms. 



EXPERIMENT CXXV. 

 Digitoxin. (Frog 1 : General Action.) 



1. Destroy the cerebrum only of a frog and inject one 

 cubic centimeter of digit oxin solution (one cubic centimeter 

 equals one milligram dissolve the digitoxin in a few drops 

 of alcohol and then dilute with water, adding more alcohol 

 if necessary to prevent precipitation of the drug. Use as 

 little alcohol as possible.) Put the frog in a quiet place and 

 see if any generalized symptoms appear. Does it have con- 

 vulsions! If the frog dies at any time immediately cut 

 open the chest and observe carefully the condition of the 

 heart. Has it just stopped beating or is it still pulsating? 

 Digitalis solutions are often standardized by giving just a 

 sufficient dose of the preparation to stop the heart of a frog 

 in one hour. This dose of the standard solution is taken as 

 a basis, by comparison with which newly prepared solu- 

 tions are standardized. Examine carefully the condition of 

 the ventricle and of the auricles. Are these chambers in sys- 

 tole or diastole? How do vou account for the condition? 



