98 EXPERIMENTAL PHARMACOLOGY 



a side tube and clip) to the stethograph drum and attach 

 the other end of the tube to a tambour which writes on 

 the drum. The respiratory record should be adjusted to 

 give an amplitude of about one inch and should be re- 

 corded below the blood-pressure and about one-half inch 

 above the base line (recorded by the time signal magnet 

 on the manometer or by a signal magnet placed separately 

 on a stand). 



(f) Adjustment of Writing Points. On the drum now 

 adjust the writing point of the manometer in such a posi- 

 tion that if the blood-pressure falls very low then the writ- 

 ing point will just barely pass down to the right of the re- 

 spiratory tambour. This is an important point in te clinic 

 and must always be foreseen and provided for especially 

 if three or four tracings are being recorded at the same 

 time. The anesthetist should have maintained an even 

 anesthesia throughout these procedures. His guide is the 

 depth and regularity of the respiration. After the blood- 

 pressure record is started then it also furnishes valuable 

 information regarding the depth of the anesthesia. The 

 respiration, however, is the most important and should be 

 watched closest. While the anesthetist is personally re- 

 sponsible for the life of the animal yet it is the duty of 

 each student in the group to keep as careful and constant 

 a watch on the animal as possible. Each animal lost care- 

 lessly should be carefully checked up against the anes- 

 thetist and his group, and should be duly considered in 

 making out the respective grades at the end of the course. 



There are certain objections to this method of record- 

 ing the respiration, but it is probably the best one for 

 student use. 



(g) Other Methods of Recording Respiration. Some 

 workers record respiration by connecting the tambour to 

 the side tube of the tracheal cannula. If ether is given 

 through a bottle or if artificial respiration is suddenly 



