128 EXPERIMENTAL PHARMACOLOGY 



more titan one cubic centimeter of ethyl bromide (one-half 

 cubic centimeter is much safer). This is a powerful drug. 



6. After records are obtained empty out the vapors, 

 open the screw clamp on the tracheal cannula and allow 

 the dog to get fresh air for some time to recover. (The 

 animal, of course, thus exhales the drugs into the open 

 air. ) 



7. When the animal recovers close the tracheal clamp 

 and let the anesthesia again become as regular as pos- 

 sible. Now through the burette inject into the pan one- 

 half cubic centimeter of chloroform. Do not give too much. 

 Obtain a record and then empty out the vapor as before. 

 How does this record compare with those obtained with 

 the other drugs ! What conclusions can you draw concern- 

 ing chloroform? What class of physicians make most use 

 of chloroform? 



Can you use the closed method for anesthesia when the 

 chest is opened? This is a good point for the student to 

 consider. Does this method present any advantages over 

 the use of an ordinary ether bottle? What are the relative 

 disadvantages ? 



8. Put about one cubic centimeter of chloroform into a 

 ciood dental syringe carrying a small short needle. Now 

 lift up the right femoral artery on an aneurism needle an 1 

 at the same time let an assistant press down on the cor- 

 responding vein to shut off its return flow. Now with 

 great care slip the syringe needle endwise into the lumen 

 of the artery. Loosen the tension on the artery a little 

 and as the blood again flows through carefully inject the 

 chloroform. Feel of the leg. Is there produced a pro- 

 found change in the tissues! If not, repeat the injection 

 into the other femoral artery. 



9. Kill the dog by asphyxia. Open the abdomen and 

 dissect out and examine the spleen, pancreas and left kid- 

 ney. To what is the spleen attached ? Place it inside an 



