BY DR. LAUDER BRUNTON. 505 



** 151. Mode of Producing Biliary Fistula in 

 Guineapigs. Chloroform the animal and secure it on the 

 rabbit-support. Make an incision from an inch to an inch and 

 a quarter long through the abdominal parietes in the linea 

 alba from the xiphoid process downwards. The pyloric end of 

 the stomach is thus exposed. Pull gently on the stomach 

 until the duodenum is brought into view. The part correspond- 

 ing to the superior transverse part in man forms a loop with 

 its convexity directed towards the diaphragm, into the top of 

 which convexity the ductus ckoledochus enters. Tie the duct in 

 this situation, then seize the gall bladder with a pair of forceps. 

 It is always full, and cannot be missed if the forceps are passed 

 immediately under the edge of the costal cartilages. Make a 

 small incision into the gall bladder, introduce a canula and tie 

 it in. The diameter of the canula should be from two to three 

 centimetres, and the end to be inserted should have a project- 

 ing rim. This can be made very readily by heating the end of 

 a piece of glass tubing of the proper size, and pressing it, while 

 hot, against a flat piece of iron. Sew up the wound, leaving 

 the free end of the canula outside. The bile in guineapigs is 

 secreted in very large quantities, being as much as 7.3 grammes 

 in an hour per kilogramme of bod}' weight. It contains a very 

 small proportion of solids, about 1.3 per cent. When the bile 

 duct is tied the guineapigs die in less than twent3 r -four hours, 

 but when it is not tied they will live for a week. The bile is se- 

 creted wider a very low pressure. For estimating this pressure, 

 prepare a manometer by attaching a piece of glass tubing, 

 eighteen inches long, to a wooden or pasteboard scale. Fit an 

 India-rubber tube to its lower end, fill the manometer and tube 

 with water, and close the latter with a clip. Tie the ductus 

 choledochus of a guineapig, and secure a canula in its gall 

 bladder. Having ascertained that the water in the manometer 

 stands at about 100 millimetres above the zero point, place the 

 tube in a horizontal position at the same level as the canula. 

 Connect the India-rubber tubing with the canula, and remove 

 the clip. As the bile is secreted, the column of water advances, 

 and the rapidity of secretion is thus indicated. When it 

 reaches 150 millimetres on the scale, raise the tube to a vertical 

 position. If the maximum pressure under which secretion 

 occurs in the animal experimented on be used, the water will 

 descend in the tube, but if not, it will continue to rise. 



** 152. Absorption by the Liver. The bile which has 

 been secreted by the liver is re-absorbed either when the pres- 

 sure is diminished in the bloodvessels, or when it is increased 

 in the bile capillaries (Heidenhain) ; jaundice may thus be pro- 

 duced in two ways. To show absorption from diminished 

 pressure in the bloodvessels, compress the aorta just under- 

 neath the diaphragm. The pressure in the manometer some- 



