DIGITALIS. 129 



DIGITALIS. 



1. Into the thigh lymph sac of a pithed frog inject 0.5 mil standardized Tincture 

 Digitalis, diluted with an equal amount of Ringer's solution. Expose the heart, and 

 keep it under observation for an hour or more, if necessary. Note variations in rates 

 of auricles and ventricle; size, strength, and duration of diastole as compared with 

 systole ; color changes, etc. Keep heart moistened with Ringer's. 



2. Pith a frog and secure normal heart tracings with a slow-timed drum, with an 

 occasional curve on the fast drum. Administer by thigh lymph sac 0.5 mil diluted 

 Tincture Digitalis. Continue tracings with slow drum, with occasional typical heart 

 curves on the fast drum, until heart ceases beating. Compare results with those 

 obtained in preceding experiment. 



3. Pith a large frog; expose the heart, and secure normal tracings. Adjust 

 apparatus for perfusion in situ with Infusion Digitalis (freshly made, and with salts 

 added to the equivalence of Ringer's solution). Continue tracings until heart ceases 

 beating, noting all objective and graphic variations. 



4. Select 2 medium cats of equivalent weight and condition. Record normal 

 heart-rate and respiration. To one give 0.5 mil Tincture Digitalis (diluted) by stom- 

 ach ; to the other give 3 mils freshly made Infusion Digitalis. Take regular observa- 

 tions of these two for several hours. 



5. Select a large cat or medium-sized dog; etherize, and obtain the usual mechan- 

 ical records of respiration and circulation. Into the jugular vein, at the rate of i mil 

 a minute, run freshly made Infusion Digitalis (salted to be equivalent to Ringer's solu- 

 tion, and kept at 39 C.). Take continuous records until animal expires. 



6. Take 2 subjects of approximately similar weight, condition, and temperament. 

 Obtain normals of pulse-rate, pulse energy, volume wave (by sphygmogram), respira- 

 tion, blood-pressure, and temperature. Also, by auscultation, study quality and rhythm 

 of apex beat. Then to one administer by mouth i mil Tincture Digitalis; to 

 the other, 8 mils of fresh Infusion Digitalis. Take regular records every 10 minutes 

 for 3 hours ; then every 6 hours, until circulatory condition returns to normal. 



Report if there be any alteration in the degree of kidney activity. 



7. In the hospital make as many studies as opportunity permits on sundry cases 

 receiving Digitalis treatment, using all the methods indicated in preceding experiment. 



Because of the cumulative effect of Digitalis, caution must be exercised in deter- 

 mining what may be the present "normal" for the patient under study. 



8. Write a concise summary of your findings in the laboratory ; state what diver- 

 gencies you may have observed in the hospital ; and check all these with references 

 from recent literature. 



