ASPHYXIA AXD RESUSCITATION 101 



repeated two or three times to secure more sets of rec- 

 ords. Now inject one-fonrth cubic centimeter of adren- 

 aline. Do you get a normal effect? Ask the instructor 

 about the appearance of this record. You may need a 

 larger dose. Compare the effects of ether with those of 

 chloroform on the blood-pressure and respiration. Which 

 do you consider safer? Why? 



6. Allow the animal to recover. Then place some ethyl 

 bromide (3 or 4 c.c.) in a second milk bottle and attach it 

 to the tracheal cannula. Compare the action of this drug 

 with that of ether and chloroform. Learn the odor of 

 each of these drugs. 



7. If Harvard kymographs are being used one student 

 should see to it that at least one well smoked extra drum 

 is always available. Allow the animal to return to a satis- 

 factory condition and then close off both openings from 

 the tracheal cannula. The animal will soon become as- 

 phyxiated. Be sure you secure a good tracing of this. 

 Observe carefully the changes in blood-pressure and res- 

 piration. How do you explain these? How do the 

 respiratory movements affect the blood-pressure? Con- 

 tinue the asphyxia until either the heart or the respiration 

 finally stops. What is the immediate cause of death? Now 

 open the tracheal cannula and at once give the animal 

 artificial respiration (the ether should be removed) either 

 with a hand bellows, or better, by means of a special 

 respiration machine (Fig. 360). Inject one cubic centi- 

 meter of adrenaline solution. The lungs should be inflated 

 about twenty or twenty-five times per minute. Does this 

 affect the heart or respiratory center? Continue it for 

 ten minutes if the animal does not recover sooner. Stop 

 when you detect sufficient signs of recovery and allow the 

 animal to return to normal. Now give the animal suffi- 

 cient chloroform to stop both heart and respiration. Im- 

 mediately apply artificial respiration and try to revive the 

 dog as you did before. Compress the chest over the heart 



