GALL BLADDER. 143 



nected to a piston-recorder. This led to the discovery that the effects 

 of apparent contraction observed in our tracings, and described by Doyon 

 as the true and sole effect of stimulation of the sympathetic nerve- 

 supply, were all produced equally well in the record taken from the 

 control balloon. Whether the splanchnic nerves were faradised or 

 adrenalin given intravenously this "artificial gall-bladder" always 

 simulated contraction, even when the tracing from the gall-bladder 

 itself indicated pure relaxation. 



It was clear, therefore, that one of the effects complicating our 

 records was the swelling of the liver which is caused by stimulation 

 of the splanchnic nerves, and still more by the injection of adrenalin. 

 The effect of stimulating the sympathetic nerve-supply was accordingly 

 reinvestigated after removal of this complication as far as possible. 



This was effected successfully by two methods. The first was the 

 simple separation of the gall-bladder from the liver, down to the 

 commencement of the cystic duct. This is easily performed by snipping 

 through the peritoneal investment, where it passes from the liver on to 

 the gall-bladder, inserting a finger into the opening thus made and 

 gently tearing the gall-bladder away from its attachment. Although 

 a small amount of liver substance always remains adherent to the 

 gall-bladder, the bleeding is negligible. This method satisfactorily 

 eliminates the effect of alteration in the liver volume, but irregular 

 contractions of the diaphragm still complicate the tracing, and it is 

 therefore necessary to give curare. 



The second method obviated the use of curare and the handling of 

 the gall-bladder in separating it from its attachments. Its principle was 

 to allow free expansion of the liver by destruction of the dome of dia- 

 phragm normally enclosing it and resisting its outward enlargement. The 

 chest was opened by longitudinal division of the sternum, the tendon 

 of the diaphragm slit down to the vena cava, and the diaphragmatic 

 muscle paralysed by section of the phrenic nerves. The chest was held 

 open by weighted hooks so that the halves of the diaphragm gaped widely 

 apart, the liver fell back into the cavity of the thorax, and the gall-bladder 

 was brought uppermost. The liver was thus given perfect freedom of 

 expansion, and its swelling merely raised the gall-bladder as a whole to 

 a slight degree. 



By both these methods we obtained uniform results. Under normal 

 conditions that is, unless both the blood-pressure and the tone of the 

 gall-bladder had fallen very low, as at the end of a long experiment 

 relaxation was the invariable result of faradising the right splanchnic 



