184 PRACTICAL HISTOLOGY. 



in cold methylated spirit, to cause the gelatine to consolidate 

 rapidly, and so prevent its escape. After several hours, or 

 a day, the preparation is removed from the alcohol, and 

 treated as may be desirable. 



342. For the injection of the kidney the organ should 

 not be removed from the animal, because of the anastomoses 

 between the renal and lumbar vessels. The nozzle should 

 be placed in the renal artery close to the aorta. 



343. For the injection of the liver from the portal vein, 

 and the lung from the pulmonary artery, salt solution should 

 first be injected, the right and left auricles of the heart be- 

 ing respectively opened to permit the blood to escape. 



344. Injection of Lymphatics. The puncture method 

 for the injection of lymphatics was introduced by Ludwig, 

 and simply consists in thrusting the sharp needle-like nozzle 

 of a Wood's syringe (the syringe of Pravaz of continental 

 writers) into various textures, and driving the fluid wherever 

 it will go. e.g. In the case of the testis, if the nozzle be thrust 

 through the tunica albuginea after death, and the injection 

 driven into trie gland substance, it very readily finds its way 

 into the lymphatics, and runs along them even as far as the 

 thoracic duct, which may be thus injected. The chain of 

 lymphatics in the leg of the dog can be easily demonstrated 

 by simply thrusting the nozzle of the syringe into the pad 

 of the foot after death, and pushing the fluid onwards by 

 compressing the limb from below upwards. The lymphatics 

 of mucous membranes and aponeuroses may be injected in 

 the same manner. A watery solution of Briicke's blue 

 ( 333)? or the turpentine or chloroform solution of alcan- 

 nm ( 335)> or asphalt ( 334A) may be employed. For 

 ordinary demonstrations the blue is the best. 



345. As the chloroform and turpentine used in these 

 fluids is apt to destroy the cement of the fastenings of the 

 syringe, they may be injected by an apparatus made of a 

 glass tube drawn to a fine point attached to a piece of 

 caoutchouc tubing, which is filled with the injection mass, 

 and closed by a ligature at the other end. On pressing the 

 elastic tube with the finger the fluid is expelled. 



346. Injection of Bile Ducts. Inject the portal vein 



