1907.] The Pressure of Bile Secretion^ etc. 519 



or by opening the inferior vena cava in the thorax. After anaesthesia was 

 complete, the animal was partially immersed in the supine position in a large 

 bath of 0*9 per cent, salt solution kept at a constant temperature of 37° C. 

 The abdomen was opened and the cystic duct clamped by a small strong clip 

 near the gall bladder. A silver cannula was inserted into the common bile duct 

 and tied in position there. A fine piece of rubber tubing was slipped over 

 the end of the cannula and attached to the lower end of a vertical piece of 

 glass tubing 1 mm. in internal diameter. A millimetre scale was attached 

 behind it, and so arranged that it and the glass tube could be raised or 

 lowered to adjust the zero mark. The rubber tubing had in it a T-piece, from 

 the third limb of which another piece of tubing led off to the side of the bath, 

 and was so arranged that when open the drops of bile fell on an electric 

 marker, by means of which the rate of secretion at zero pressure could 

 be recorded on a slowly moving drum. The abdomen was freely opened, so 

 that movements of the diaphragm affected the pressure as little as possible ; 

 in this way the respiratory spring of the column of bile was diminished and 

 rarely exceeded 1 or 2 mm. The opening in the abdomen was covered with a 

 sheet of cotton wool, and the animal was then entirely immersed, with the 

 exception of the head and neck, in the warm salt solution. The vertical glass 

 tube was adjusted so that the zero mark was at the level of the hepatic duct 

 at the portal fissure. Part of the liver was thus above the level of the zero 

 mark, but the greater part of it was at a lower level. This we believe to be 

 as exact a method as that adopted by Friedlander and Barisch. It is certainly 

 advantageous to maintain the temperature of the animal by warm saline when 

 the abdomen is open, seeing that the experiment may be of some considerable 

 duration. 



In some animals we also determined the blood pressure in the splenic vein 

 as near the portal vein as possible. The pressure was recorded by means of 

 an apparatus similar to that described for recording the bile pressure. In this 

 case a T-tube led to a pressure bottle containing a saturated solution of sodium 

 carbonate, and the apparatus was filled and the pressure recorded in terms of 

 a column, of that solution. Before removing the clip from the vein after 

 insertion of the cannula, the fluid was allowed to fill the vertical tube to a 

 height approximating to the probable blood pressure ; the pressure bottle was 

 then shut off by a clip, and the clip on the splenic vein removed. The method 

 was found to give good results. 



Occasionally we made intravenous injections of extract of duodenal mucosa 

 or of bile into a jugular vein. 



In beginning an observation we usually recorded the rate of flow of bile 

 secretion at zero pressure by the marking of drops in the way described on 



2 p 2 



