CASUAL URINARY CONSTITUENTS. 733 



V. CASUAL URINARY CONSTITUENTS. 



The casual appearance, in the urine, of medicinal agents or of urinary 

 constituents resulting from the introduction of foreign substances into 

 the organism is of practical importance, because such compounds may 

 interfere in certain urinary investigations; they also afford a good means 

 of determining whether certain substances have been introduced into the 

 organism or not. From this point of view a few of these bodies will be 

 spoken of in a following section (on the pathological urinary constituents) . 

 The presence of these foreign bodies, in the urine, is of special interest in 

 those cases in which they serve to elucidate the chemical transformations 

 which certain substances undergo within the organism. As inorganic 

 substances generally leave the body unchanged, 1 they are of very little 

 interest from this standpoint; but the changes which certain organic 

 substances undergo when introduced into the animal body may be studied 

 by the transformation products as found in the urine. 



The bodies belonging to the fatty series undergo, though not without 

 exceptions, a combustion leading toward the final products of metab- 

 olism ; still, often a greater or smaller part of the bodies in question escape 

 oxidation and appear unchanged in the urine. A part of the acids belong- 

 ing to this series, which are otherwise decomposed into water and carbon- 

 ates and render the urine neutral or alkaline, may act in this manner. 

 The volatile fatty acids poor in carbon are less easily oxidized than those 

 rich in carbon, and they therefore pass unchanged into the urine in 

 large amounts. This <is especially true of formic and acetic acids 

 (SCHOTTEN, GREHANT and QUINQUAUD 2 )-, but as to oxalic acid authorities 

 disagree. In birds, according to GAGLIO and GIUNTI, it is not oxi- 

 dized. In mammals it is in great part oxidized, according to GIUNTI, 

 while GAGLIO and POHL claim that it is not destroyed. MARFORI and 

 GIUNTI claim that in human beings oxalic acid is in great part oxidized. 

 The recent investigations of SALKOWSKI, PIERALLINI, STRADOMSKY, 

 KLEMPERER and TRITSCHLER and especially those of HILDEBRANDT and 

 of DAKIN, S where oxalates were introduced subcutaneously, show that 

 oxalic acid, when introduced in medium quantities, is in great part 

 oxidized in the animal body. Tartaric acids act differently, according 



1 In regard to the behavior of certain of these bodies, see Heffter, Die Ausscheidung 

 korperfremden Substanzen im Ham, Ergebnisse d. Physiol., 2, Abt. 1. 



2 Schotten, Zeitschr. f. physiol. Chem., 7; Grehant and Quinquaud, Compt. rend., 

 104. 



3 Gaglio, Arch. f. exp. Path. u. Pharm'., 22; Giunti, Chem. Centralbl., 1897, 2; 

 Marfori, Maly's Jahresber., 20 and 2"; Pohl, Arch. f. exp. Path. u. Pharm., 37; Sal- 

 kowski, Berl. klin. Wochenschr., 1900; Pierallini, Virchow's Arch., 160; Stradomsky, 

 ibid., 163; Klemperer and Tritschler, Zeitschr. f. klin. Med., 44; Hildebrandt, Zeitschr. 

 f. physiol. Chem., 35; Dakin, Joiirn. of biol. Chem., 3. 



