464 JACOB ROSENBLOOM 



oxalic acid producers. For a long time the nucleoproteins have been looked 

 on as the material for the formation of oxalic acid. Upon treatment with 

 oxidizing reagents (permanganate, iron chlorid) uric acid is easily trans- 

 formed into oxalic acid. Frerichs and Wohler observed an increase in 

 oxalic acid excretion after feeding with ammonium urate; but later with 

 exact methods this finding could not be confirmed. Lommel once ob- 

 served an increased output of oxalic acid after feeding with great quanti- 

 ties of calf thymus. But Luthje, Mohr and Salomon could not verify 

 this result. Besides Cipollina found 11.5 to 25.4 mg. oxalic acid per kilo 

 in the calf thymus; and as Lommel had given his subjects 1500 gm. of 

 pulp, this preformed oxalic acid was sufficient to account for a rise of 30 

 mg., the maximum which Lommel observed. There are no observations 

 which force us to regard oxalic acid as a product of nucleoprotein metab- 

 olism. 



Oxalic acid excretion has, as Lommel showed, no relation to protein 

 metabolism. But it undergoes, however, an increase after feeding with 

 gelatin and gelatinous tissues (Lommel, Mohr and Salomon). Klem- 

 perer and Tritschler have concluded that it is the glycocoll of gelatin 

 NrLCHoCOOH that forms the oxalic acid. According to the investi- 

 gations of E. Fischer and of Levene and Beatty gelatin contains 16.5 to 

 19.25 per cent of glycocoll. Glycocoll occurs also in other protein foods 

 100 gm. fowl protein contains 3.15 gm. ; 100 gm. syntonin from oxflesh 0.5 

 gm. but these amounts are so small that they furnish no conclusion in 

 metabolism experiments. Satta and Gastaldi, contrary to Klemperer and 

 Tritschler, found that glycocoll feeding produced no increased oxalic acid 

 output in dogs. 



Similar negative results have been found in man. W. Thorner fed 

 five persons six times with glycocoll in amounts from 2 to 5 gm. and in no 

 case observed increased oxalic acid output. 



Long ago Kiihne expressed the suspicion that creatin, 



NH 



TTAT r\^-^ i 2 p-rr prjOTT 



XIIN ^^"vr/r^TT \ ^-tJ-z-^^'^-'-ti 



passes over into oxalic acid. 



Klemperer and Tritschler found this suspicion verified. Creatin 

 .occurs in varying quantities in the muscles of vertebrates, being greatest in 

 that of birds. According to Monari the amount is increased by work, if 

 the conclusion of Klemperer and Tritschler is correct. The observations of 

 G. Meissner and C. Voit that creatin given to an animal reappears entire 

 in its urine are opposed to it. W. Thorner ate during two days seven 

 partridges without having any increase in the oxalic acid of the 

 urine. 



The preformed oxalic acid of the food and that which is formed out of 

 the food and in the body appears in the urine as oxalate. Many have tried 

 to correlate the precipitation of the calcium salt with many morbid condi- 



