IO2 HOW TO WORK 



drops from the divided extremity of the duct. The bile soon became 

 thinner owing to its dilution with water which permeated the inter- 

 vening membrane, and entered the ducts. These long narrow highly 

 tortuous channels were thus effectually washed out from the point 

 where they commenced as tubes not more than i-joooth of an inch 

 in diameter, to their termination in the common duct, and much of 

 the thick layer of epithelium lining their interior was washed out at 

 the same time. The water was removed by placing the liver in cloths 

 with sponges under pressure for twenty-four hours or longer. All the 

 vessels and the duct were then perfectly empty and in a favourable 

 state for receiving injection. The duct was first injected with a 

 coloured material. Freshly precipitated chromate of lead, white lead, 

 vermilion, or other colouring matter may be used, but for many 

 reasons to which I have alluded, the Prussian blue injection is the 

 one best adapted for this purpose. It is the only material which 

 furnishes good results when the injected preparations are required to 

 be submitted to high magnifying powers. Preparations injected in 

 this manner should be examined as transparent objects, p. 90. They 

 may be mounted in the ordinary preservative fluids or in Canada 

 balsam, but glycerine forms the most satisfactory medium for their 

 preservation. 



I have recently succeeded in making most perfect injections of 

 the ducts of the liver which demonstrate conclusively the cell con- 

 taining network of the lobule and its connection with the finest gall 

 ducts. The injection may be seen around the hepatic cells as they 

 lie in the tubes of the network. 



189. Of Injecting' Lymphatic Vessels. It is very difficult to find 

 and insert a pipe into a lacteal or lymphatic vessel. When it is desired 

 to inject these tubes it is usual to insert the pipe into the large trunk 

 of the thoracic duct. I have, however, found that by injecting water 

 into the blood vessels, the lymphatics and lacteals of a part of the 

 body or of an organ become distended by the transudation of the 

 fluid, and in this distended state it is easy to insert the pipe. 

 The pipe having been tied in the vessel, the water is absorbed as 

 described in 188, and the injection may then be forced in, care 

 being taken to use very gradual pressure, so that the coats of the 

 lacteal or lymphatic may be sufficiently stretched to allow the injec- 

 tion to pass between the valves, without being impt tired. In this way 

 I have succeeded in making beautiful injections of the finest lym- 

 phatics of the liver. (Archives, vol. I, p. 113.) PI. XXIV, fig. 160. 



Sometimes lymphatics may be injected by extravasation from a 

 duct and more rarely from a vessel. I have often injected the 

 lymphatics of the liver when forcing the injection into the duct. 



