COCAINE, NOVOCAINE, BARIUM, ADRENALINE 353 



with normal salt solution. Meanwhile the drug is being 

 carried to the other gastrocnemius muscle. 



When all is ready take a normal fatigue tracing on the 

 lower part of the drum. Then lower the drum and reverse 

 the frog board and corresponding pieces of apparatus as 

 described under caffeine (Experiment XL VII, page 245). 

 Ligate the left thigh and take a fatigue tracing from the 

 left gastrocnemius muscle which has in the meantime come 

 under the influence of the cocaine. How do the two curves 

 compare as to height of contractions and relative amount 

 of work done! If there is a difference to what is it due! 

 Are any nervous structures involved? Are you sure the 

 rate of stimulation remained the same in both tracings? 

 Would a slight variation in this produce much effect on 

 the tracings? How does the action of cocaine compare 

 with that of caffeine on muscular work? 



EXPERIMENT XCVII. 



Cocaine, Novocaine, Barium, Adrenaline. (Dog- or Cat: 



Respiration, Blood-pressure, Intraocular Pressure, 



Local Vascular Action and Intestinal 



Contractions.) 



1. Arrange a dog (or cat) for recording blood-pressure, 

 respiration and intestinal contractions, the latter by means 

 of the finger cot, catheter, burette and tambour method. 

 While the abdomen is open pick out a small area of the in- 

 testinal or mesenteric wall where the tissues look pink 

 (many small vessels) and paint the area with cocaine hy- 

 drochloride solution (two per cent). Also paint a second 

 area with novocaine solution (two per cent). Do not ex- 

 pose the viscera more than can be helped but observe these 

 two areas closely for several minutes to see if any change 

 in the appearance of the tissues occurs. If so how do you 

 explain it? On a third small area of the intestine put one 



