288 



EXPERIMENTAL PHARMACOLOGY 



centimeter equals one-half milligram). (Muscarine one 

 cubic centimeter equals one milligram may be substituted 

 for one of the last two drugs or be used separately if it 

 is available.) 



Observe carefully the apparatus shown in Fig. 255. 



Inlet 



Derail /o snow anqle 

 of wire brace. 



^ 



i ^- x A* jf 



.'^.'&*' '- -'Mi Fl3T1 ^ ~fJ 



-.j^ ^a wed ed^e 



' ^y'^/ 



of sternum 



Diaphragmatic 



surface 



Fig. 255. A form of apparatus (approximately one-half natural size) made of sheet 

 brass to place in the chest to hold the walls rigidly wide open and air tight while the 

 records of changes in the caliber of the bronchioles are taken. A dotted circle in the 

 center of the curved plate shows where a window may be placed to great advantage if 

 sufficient shop facilities are available to do this. The window may be made of a sheet 

 of celluloid (such as is used in automobile curtains) or of glass, and if the window is 

 removable this also adds to its usefulness. The curved wire at the base is made of 3/16 

 inch brass rod. Any tinner should easily be able to make up at a very small cost such a 

 piece of apparatus, which can be made of "tin" (tinned iron) or galvanized sheet iron. 

 The instrument may be used for recording bronchial contractions by use of either posi- 

 tive or negative artificial respiration, but the latter (aspiration of the chest) is greatly 

 to be preferred. (For the method of use see text.) 



