1892.] The Influence of the Kidney on Metabolism, 



39 



described above does not follow destruction of the renal plexus, nor 

 does it follow free incision of the kidney with subsequent suturing of 

 the damaged organ. It is a phenomenon closely connected with the 

 removal of large quantities of kidney, i.e., half of one kidney and 

 the whole of the second. Inasmuch as the phenomena do not ensue 

 after the first and more severe operation, but only after the second 

 and comparatively trivial operation, it must be concluded that they 

 are more related to the quantity of kidney removed than to the shock 

 of the operation, or to any reflex disturbance produced by the 

 operation. 



The excess of urea in the muscle over that in the liver and brain 

 might be considered as evidence of its production in the muscles. 

 That this is not necessarily the case is shown by the results of the 

 injection of large quantities of urea into the circulation of normal 

 dogs. The dogs were anaesthetised with chloroform, the ureters 

 ligatured, and the urea then injected into the external jugular. After 

 from one to three hours the animals were killed by bleeding, anl the 

 tissues examined, .as described above. 



Dog's 

 weight. 



Amount 

 of urea 

 injected. 



Time. 



Amount of urea in 



Blood. 



Muscle. 



Liver. 



Brain. 



20 lbs. 



10 grams. 



2f hours. 



-11 p.c. 



0-08 p.c. 



0'04 p.c. 



? 



13-5 lbs. 



20 grams. 



1£ hours. 



-25 p.c. 



35 p.c. 



0*22 p.c. 



0-2 p.c. 



From these and other observations, we see that the percentage of 

 urea in the muscles is greater than in the case of the liver and brain 

 after intravenous injection, and that it may exceed that of the blood. 

 The smaller percentage in the liver is not dependent upon the excre- 

 tion of urea through the bile duct, because after ligature of the bile 

 duct the percentage in the liver is still lower than that of the 

 muscles after the intravenous injection of urea. After ligature of both 

 ureters, and after double nephrectomy, the same distribution of urea 

 is found in the tissues. 



In all the following cases the animals were killed three days after 

 the operation. 



The large quantity of urea present in the muscles under all these- 

 different circumstances cannot as yet be regarded as evidence of its, 

 direct production in the muscles. 



