498 DIGESTION. 



appears to take place in the blood during its passage through 

 the liver (Grehant). Though a positive result has been 

 obtained by so many observers, Naunyn failed to detect bile 

 pi-iiu'iits in the urine of rabbits after the injection of haemo- 

 globin, either subcutaneously or into the jugular vein, and 

 attributed the success of others to their experiments having 

 been made on dogs, in whose urine bile pigment is normally of 

 frequent occurrence. He noticed them, however, in rabbit's 

 urine, when blood in which the corpuscles had been destroyed 

 by freezing or ether, was injected into the intestine, so that 

 the hemoglobin absorbed from it, or set free by the action of 

 the ether on the blood of the portal vein, passed through the 

 liver before reaching the general circulation. Naunyn's experi- 

 ments, also, have been repeated by Wolff and Wickham Legg, 

 with a n-egative result. 



In performing them proceed as follows: Narcotize a rabbit 

 with chloroform, shave the hair from the belly, make an incision 

 about 1| centimetres in length in the linea alba a little above 

 tin- middle point, between the base of the xiphoid cartilage and 

 the symphysis pubis. Seize a coil of small intestine with a pair 

 of artery forceps, and hold it opposite the wound, without draw- 

 ing it forward more than is just necessary. Inject 2 cub. cent, 

 of ether into the intestine close to the points of the forceps with 

 a subcutaneous syringe. Tie a ligature round the point 

 wounded by the syringe and forceps ; attach the intestine by 

 it to the abdominal wall, and close the wound with a point of 

 suture. The inhalation of chloroform is too short to produce 

 of itself bile pigment in the urine, and it greatly facilitates the 

 operation. 1 Examine the urine of the rabbit for bile pigments 

 an hour or two after the operation, and again next morning. 

 To get the urine, hold the rabbit over a large beaker, compress 

 the abdomen with the palm of one hand, and press with the 

 thumb of the other on the bladder just above the pubes, push- 

 ing it well down into the pelvis. 



139. Relation between the Coloring Matter of Bile 

 and that of Urine. The urinary pigment is supposed to be 

 derived from that of bile, as a substance which presents similar 

 spectroscopic characters can be extracted from bile, or produced 

 by deoxidation from bilirubin. In the organism, bile pigments 

 are probably reduced by hydrogen, or other reducing agents 

 present in the intestine. 



Wlicn dog's bile is extracted with dilute hydrochloric acid 

 and filtered, the filtrate has a reddish or reddish-yellow color, 

 and en spectroscopic examination presents a band close to F, 



1 The writer has failed to observe bile pigments in the urine, either 

 after the injection of bile acids into the veins, or of ether or dissolved 

 blood corpuscles into the intestines. 



