LACTIC ACID IN URINE 463 



troduced dextrorotary lactic acid, even when administered in 

 large amounts, is almost completely consumed, according to 

 observations by J. Parnas 28 in Hofmeister's laboratory. 

 Laevo-rotary lactic acid is partly changed, partly excreted 

 unchanged ; after introduction of racemic lactic acid an ex- 

 cess of laevo-rotary acid is eliminated. From observations 

 made in the Vienna Pharmacological Institute it seems that 

 the unconsumed fraction of lactic acid is excreted partly as 

 such, partly, however, in the form of other ether-soluble 

 acids. 29 



Passage of lactic acid into the urine is observed especially 

 after severe muscular efforts, in epilepsy and eclampsia, in 

 hepatic affections (acute yellow atrophy, phosphorus poi- 

 soning, etc.), in oxygen deficiency, and, too, in geese after 

 extirpation of the liver. 30 The fact that uric acid contains 

 a tricarbon nucleus by no means justifies the assumption 

 that the lactic acid excreted in the last instance is a sub- 

 stance which would have been transformed into uric acid 

 under normal conditions. 31 The general impression is 

 given that lactic acid appears in the urine in conditions in 

 which its normal combustion is lowered. However, it is 

 impossible as yet to definitely formulate how, where and 

 why this is the case ; and from appearances it is likely that 

 considerable time will elapse before this is possible. 



FATE OF BODY-FOREIGN SUBSTANCES IN THE ECONOMY 



Having in the course of the preceding lectures attempted 

 in one way or another to discuss in detail the fates of the 

 most important foodstuffs, proteins, carbohydrates and fats, 

 it may be well to round out our knowledge by endeavoring 



28 J. Parnas (F. Hofmeister's Lab., Strassburg), Biochem. Zeitsehr., 38, 

 53, 1912. 



29 E. Neubauer (Vienna Pharmacological Institute), Arch. f. exper. Pathol., 

 61, 387, 1909. 



80 Literature upon Lactic Acid Excretion: A. Ellinger, Handb. d. Biochem., 

 S f , 651-653, 1910. 



81 Cf. J. B. Leathes, Ergebn. d. Physiol., 8, 360, 1909. 



