ACTION OF OPIUM ALKALOIDS 211 



produced may last for some time and is very liable to cause 

 the heart to stop (possibly from the extra strain). The re- 

 spiratory movements of the dog should stop entirely. If 

 they do not, wait a little while and make a second chloro- 

 form injection. Sometimes the diaphragm will contract 

 at every beat of the heart. This is due to an action cur- 

 rent generated by the heart where the phrenics pass over 

 it. These nerves should therefore be cut between the heart 

 and the diaphragm (while the chest is open). 



The animal should now lie quietly and the blood-pressure 

 should be about one inch or a little less above the base line 

 on the drum. Just above the blood-pressure should be the 

 lung volume record (about two or three inches in height), 

 and above this about one-fourth inch should lie placed the 

 tambour record for the bladder which is now connected up 

 to the mercury bulb. Take about one inch of normal trac- 

 ing. If everything is satisfactory then inject five cubic 

 centimeters of heroine (or codeine) solution. Is there any 

 change in the bladder? If not it may have been completely 

 empty and contracted before the drug Avas injected. Do 

 you get any lung volume change"? How do you account 

 for this? What mechanical factors are involved? How 

 does positive artificial respiration differ from natural res- 

 piration? As soon as you get a well marked action from 

 the drug injected, then run into the vein one cubic centi- 

 meter of adrenaline. How does this affect your record? 

 How do you account for this? Of what clinical use might 

 this be? What effect does this have on the bladder? How 

 do you explain this? 



Wait until the records return to normal and then inject 

 eight cubic centimeters of the second alkaloid (codeine 

 or heroine, or vice versa, depending on which drug was in- 

 jected the first time). How does this drug affect the blad- 

 der and lungs? The dose is larger than the first one given. 

 How do these doses compare with those given to dogs to 

 narcotize them before operations? Has the first injection 



