304 EXPERIMENTAL PHARMACOLOGY 



the heart beats well. A marked effect should be produced. 

 Explain the action of the drug in this case. It will be in- 

 structive if you can compare the action of nicotine on the 

 turtle lung with the corresponding action on a dog's lung. 



EXPERIMENT LXXV. 



Nicotine, Arecoline, Atropine. (Dog: Blood-pressure, Res- 

 piration, Limb Volume, Intestinal Contraction.) 



1. Etherize a dog and arrange for blood-pressure, res- 

 piration and intestinal contraction (Fig. 24(i). Examine a 

 plethysmograph for the hind limb of a dog (Fig. 269). 

 Rub soapsuds around the left hind leg close up to the 

 body of the animal. Take a razor and shave the hair all 



Fig. 269. Method of application of a plethysmograph to the hind leg of a dog. 



off ill band about one and one-half inches wide entirely 

 around the leg. (A strong solution of sodium sulphide 

 may be used to remove the hair by rubbing the solution 

 over the selected area. The hair can then be readily scraped 

 off. But this is a filthy method. A cheap safety razor is 

 best.) The hair must be removed or the rubber band of 

 the plethysmograph will leak air around the limb. Attach 

 the plethysmograph as illustrated and connect it to a small 

 howled very sensitive tambour. From above down, the 

 records on the drum should be leg volume, intestine, 

 blood-pressure, respiration, base line and time signal. In- 

 jecting burettes should be placed in the right femoral and 

 the left jugular veins. These contain nicotine (one-half 

 per cent) and adrenaline. 



