RATE OF OXYGEN CONSUMPTION 189 



by simply watching the lever as it writes on the drum. A 

 monkey wrench is better than the regular wheel wrench to 

 control the valve on the oxygen tank where careful regu- 

 lation is needed. It is very desirable to have the tank 

 fastened doAvn with a clamp to the table (see Figs. 112 and 

 113). 



To obtain urine for tests the abdomen is opened over the 

 bladder which is caught in a hemostat at the urachus (Fig. 

 179). The bladder is then raised a little and a second 

 hemostat is clamped on the opposite side of the urachus 

 in such a manner that an opening can be cut with a scalpel 

 or scissors just between the tips of the hemostats. Be- 

 fore this opening is made place a twine string around the 

 upper part of the bladder (just below the points of the 

 hemostats) and tie it loosely. Open the bladder (do not 

 allow any urine to escape or blood to run down into the 

 bladder if it can be avoided) and quickly insert the blad- 

 der cannula. Tie the ligature and replace the bladder 

 within the abdomen which is closed by hemostats. Catch 

 the urine in a beaker and test some early to see if it con- 

 tains glucose. 



When all apparatus is adjusted start the drum and 

 take several records of the oxygen consumption in order 

 to become familiar with the method and to get some nor- 

 mal records. Your success will depend largely on your 

 ability to determine exactly when to stop and start the 

 drum and to judge when the lever has gone high enough. 

 This is the most diffcult part of the experiment and should 

 alivays be done by that member of the group who is best 

 able to carry out this work. 



Your "normal" oxygen records should be almost exactly 

 alike both in form and in the distance they occupy on the 

 drum. 



Inject one cubic centimeter of morphine. Watch the 

 oxygen records closely and make your changes promptly. 

 When the records all return to normal inject three or four 



