510 OF SECRETION AND EXCRETION. 



Shepard at the kidney. Kreatin and Kreatinin may be obtained by the 

 action of Chloride of Zinc on concentrated urine ; but the researches of 

 Heintz 1 have shown that no Kreatin is present in fresh urine, that which 

 was formerly obtained being in fact produced by the decomposition of the 

 Chloride of Zinc compound, the Kreatinin of which takes up water and is 

 converted into Kreatin. 2 The quantity of Kreatinin daily eliminated by a 

 healthy man, living on a good mixed diet, was found by Neubauer to vary 

 from 9 to 20 grains. The maximum quantity is excreted on a flesh, the 

 minimum on a farinaceous diet (Meissner, Voit). In dogs exertion causes 

 no increase. Kreatinin is the most powerful organic base in the body. 

 Kreatin can be converted by boiling with Baryta water into Sarcosin and 

 Urea. 3 When ingested with the food it is either eliminated unchanged, or 

 it is partially converted into Kreatinin. 4 The coloring matters of the urine 

 appear to be derivatives of the biliary acids, and not of the biliary coloring 

 matters, since Bogomoloff 5 and Heynsius and Campbell 6 found that, injection 

 of the biliary acids into the blood increased the quantity of urinary coloring 

 matter, whilst injection of biliary pigments was without effect. Masius, and 

 Vanlair 7 thought they proceeded from the coloring matter of the bile which 

 underwent conversion in the intestines into stercobilin, and was partially 

 excreted in the fseces and partially eliminated by the kidneys. Jaffe 8 con- 

 sidered stercobilin to be identical with urobilin, since the absorption stria of 

 its solutions is the same and it gives the same beautiful green fluorescence 

 with chloride of zinc. Maly 9 obtained from the intestines a substance to 

 which he has applied the term Hydrobilirubin, which he considers to be a 

 derivative of cholepyrrhin, and to undergo partial absorption. 10 They may 

 all be regarded as modifications of one substance, urobilin, which gives a 

 yellow or rose color dichroizing into pink with mineral acids, and presents 

 an absorption stria between b and F. 11 These bodies, as was also noticed by 

 Carter, 12 present close analogies to the series of compounds of which Indican 

 forms the first member, and a blue coloring matter is sometimes generated 

 in disease. The Extractives of the urine contain considerable proportions 

 of carbon, whilst they are poor in nitrogen ; so that their increase will be 

 favored by an excess of carbonaceous food, an imperfect action of the liver, 

 and a low degree of respiration ; whilst on the other hand, a highly azotized 

 diet, especially if combined with active exercise, will tend to their reduction. 

 The odor of the urine appears to be due to the presence of minute quanti- 

 ties of the volatile acids, termed by Stadeler Phenylic (or Carbolic, C^HjO,, 

 HO), Taurylic (C I4 H 8 O 2 ), Damaluric (C U H U O 3 ,HO), a ud Damolic, the com- 

 position of which last is unknown. 



413. The determination of the mode and place of origin of the urinary 

 constituents, and especially of the urea and uric acid, are points of consider- 

 able interest. The solution of this question, however, demands great skill 



1 Vogel and Neubauer, On the Urine, New Syd. Soc Transl., 1863, p. 18. 



2 Kreatinin C 8 H 7 N 3 O 2 + 4HO becoming Kreatin C 8 H U N 3 O 6 . 



3 Kreatin C 8 H n N 3 <> 6 becoming Urea C,H 4 N,O. 2 and Surcosin C 6 H 7 N0 4 . 



4 Meissner, Centralblatt, 18G8i~p. '275. 



6 Bogomoloff, Centralblatt f. d. Med. Wiss., 1875, p. 210. 



6 Pfluger's Archiv, Bd. iv, p. 497. 



"> Centralblatt, f. d. Mud. Wiss., 1871, p 309. 



3 Idem, 1871, p. 465. 9 Idem, 1871, p. 851. 



10 See also Sehunck, Proceed, of Roy. Society, 1807, vol. xvi, p. 73. 



11 Thudicluim, Chemical Physiology, 1872, p. 187, gives directions for obtaining 

 Urochrom, Uromelanin, Uropittin, Ouiicholein, Omicholic ucid, and Xanthin, which 

 last Scherer and Neubauer also considered to be present in the urine. 



12 Memoirs of Manchester Med. Soc., vol. xiv, p. 293. See also KlcUinsky, Hel- 

 ler's Aruhiv, vol. vi, p. 414 ; and Thudicluim, Brit. Med. Journ., Nov. 5th, 1864. 



