354 EXPERIMENTAL PHARMACOLOGY 



drop of barium chloride solution (one per cent). Watch 

 this area for a few minutes and record your results. A 

 fourth area should be treated with one drop of adrenaline 

 solution (1:10,000). "\Vatch this spot a while and compare 

 all the areas together. AVhat conclusions and what ex- 

 planations can you offer ? 



Close the abdomen and arrange to record the intra- 

 ocular pressure (see Fig. 271). The injecting burettes con- 

 tain cocaine hydrochloride ( one cubic centimeter equals five 

 milligrams) and adrenaline (1:10,000). On the drum the 

 highest record should be the intraocular pressure, next be- 

 low the intestinal record, then the blood-pressure, respira- 

 tion and base line (showing the time intervals). 



Take a short normal record and inject one-half cubic 

 centimeter (dog) of cocaine solution. From time to time 

 cautiously inject more cocaine and note the reactions of 

 the animal to the drug. Observe the pupils, palpebral, fis- 

 sure, nictitating membrane and eye ball as a dose of the 

 drug is injected. Are there any movements of any of these 

 organs"? Continue the observations and stimulate the cor- 

 responding vagus nerve. AVhat effect does this have on 

 the palpebral fissure ? How do you explain it ? Does the 

 eye ball move ? If so what muscles do this and what is their 



*/ 



innervation? Has the intraocular pressure been affected? 



Inject one-half cubic centimeter of adrenaline while still 

 observing the eye and record the results. Explain all 

 phenomena observed. 



Continue to inject cocaine slowly from time to time and 

 watch for irregularities in the respiration. 



(The animal should not have been given any morphine. 

 It is a very good rule never to give morphine to animals 

 for ordinary experiments unless there is some special rea- 

 son for so doing. Ether is the best anesthetic, and a small 

 amount of chloretone may often be given to some advantage 

 but even this frequently causes serious cardiac or respira- 

 tory disturbances.) 



