374 STUDIES IN ADVANCED PHYSIOLOGY. 



blood is ill the liver burned still further into urea, and then 

 sent to the kidneys to be eliminated. 



We have thus seen two sources of urea in the body, one 

 derived from the immediate burning up of the excess pro- 

 teids in the liver, the other derived from the kreatin and 

 similar compounds of the tissue destruction. But the for- 

 mation of this urea occurs in both cases in the liver. The 

 kidneys take no part whatever in the production of this sub- 

 stance, but are concerned wholly and only with its elimina- 

 tion. When the diet is naturally rich in the proteids, and 

 when, therefore, increased amounts of these urea-like sub- 

 stances appear in the blood, the kidneys are frequently un- 

 able to eliminate this from the body as rapidly as it is being 

 formed, and so there is a tendency towards the accumula- 

 tion of uric compounds in various parts of the body, especi- 

 ally at the joints, producing the somewhat aristocratic 

 disease called the " gout." These uric poisons in the blood 

 serve to irritate the tissues and so produce quite abnormal 

 conditions. The remedy is, of course, the removal of these 

 poisonous salts from the blood. One of the best agents in 

 the physician's hand is some form of salicylic acid, in which 

 these salts are soluble, and which when taken into the blood 

 tends to dissolve them out of the tissues. Along with such 

 tendencies to gout the increased demands made on the kid- 

 neys may finally result in the impairment of their energies, 

 and so Bright 's Disease be induced, a disease alarmingly 

 frequent among persons addicted to a luxurious table. 



Whether the familiar rheumatism is due to an accumula- 

 tion of metabolic products in the blood is still unsettled. 

 Some look upon it as a disease due to germs, others as a 

 cold affecting nerve centers, and by still others, and possi- 

 bly most, as a result of the accumulation of lactic acid in 

 the blood. It has even been claimed by one observer that 

 it was possible to produce rheumatism artificially by an in- 

 jection of lactic acid into the system. 



