152 



EXPERIMENTAL PHARMACOLOGY 



tion in one burette and thirty per cent alcohol in the other. 

 Start the drum with a medium speed and take a short nor- 

 mal record. // even/thing is satisfactory then inject two 

 cubic centimeters of alcohol if the animal is a dog, or one- 

 half cubic centimeter if vou have a cat. From the results 



Weights ^ari 



Ventricular lever 

 Artificidl respiration 



Fig. 144. Arrangement of apparatus for recording the movements of one auricle 

 and one ventricle. The heart is held in a special holder (Fig. 145) here but sometimes 

 the pericardium is slit open and the edges are stitched to the sides of the chest so that 

 the heart lies in a sort of hammock. 



of this first dose you can estimate about what sized doses 

 the animal will be able to overcome later. This will vary 

 with each experiment and the student should early learn 

 to estimate doses of drugs of low toxicity. AVith very pois- 



