ACTION OF MORPHINE OX OXYGEX CONST MPTIOX 227 



will thus not change separate readings on the drum. This 

 automatic measuring of the oxygen saves time and should 

 be done by the student who manages the apparatus on 

 the drum. The measuring device can also be used on the 

 simple apparatus shown for Experiment XXA 7 III if de- 

 sired. 



Several very interesting and important actions of cer- 

 tain drugs can be recorded either with the apparatus 

 shown in Fig. 172 or with that illustrated in Fig. 175. 

 Thus the short, rapid, up-and-down movements of the heart 

 lever records the respiration of the animal even more ac- 

 curately than does the stethograph around the body. In 

 addition the actual relative amount of gases passing in 

 and out of the lungs at any given period can be compared. 

 And any general change in the volume of the lung con- 

 tents (contraction or relaxation of the bronchioles) is 

 well shown. For the latter purpose the short respiratory 

 excursions of the heart lever on the drum should be mag- 

 nified to write about one or one and one-half inches in 

 amplitude. 



Arrange a medium sized dog for recording blood-pres- 

 sure and respiration. The injecting burettes contain 

 adrenaline and morphine (one cubic centimeter equals 

 five milligrams). Attach the apparatus for recording 

 oxygen consumption and take a normal record. This will 

 involve at least one (and better two or three) complete 

 notches on the oxygen record. Now deepen the ether anes- 

 thesia a little (not too much) and see if this slows down 

 the oxygen consumption. What would you expect the 

 ether to do? Now r get the animal into a perfectly satis- 

 factory condition and inject three cubic centimeters of mor- 

 phine. How does this affect the oxygen record ? Can you 

 determine whether the observed result is due to a central 

 or to a peripheral action of the drug! Are there any evi- 

 dences of bronchial changes! Explain. Inject one -cubic 



