103 



EXPERIMENTAL PHARMACOLOGY 



possible this should be done with a thoroughly reliable res- 

 piration machine (Fig. 360). If this is not available then 

 use a hand bellows (Fig. 103). Prepare a needle and thread 

 and four strong twine (heavy) strings about eighteen 

 inches long. 



With the scalpel make a median longitudinal incision in 

 the skin and fascia over the sternum. The incision extends 

 from the root of the neck to the end of the xiphoid cartilage. 

 When the fascia and muscular layers come into sight a 

 number of blood vessels will be seen passing mesially in 

 pairs to the midline of the sternum where they pass into 

 the chest. Do not cut these vessels if it can be avoided 



Fig. 104. Bancage taw. 



(which is sometimes impossible). In the center line it is 

 usually possible to cut between the ends of each pair of 

 vessels and thus avoid much hemorrhage. 



If a vessel is cut clamp it with a hemostat. The bleed- 

 ing should soon cease. Have plenty of absorbent cotton 

 (in small wads) at hand to sponge off the operative field. 

 When the center line of the sternum is reached then take, 

 a saw (Fig. 104) and saw open the chest as shown in Fig. 

 105. Start tie artificial respiration as soon as any open- 

 ing is made into the chest. It is exceedingly Important to 

 keep the incision in the center line. If this is done prac- 



