THE URINE. 403 



give a blue reaction ; but when properly performed it is so extremely 

 delicate that when it gives negative results any other test for blood 

 'is superfluous. 



HELLEK-TEICHMANN'S Test. If a neutral or faintly-acid urine 

 containing blood is heated to boiling, we always obtain a mottled 

 precipitate consisting of albumin and haematin. If caustic soda is 

 added to the boiling-hot test, the liquid becomes clear and turns 

 green when examined in thin layers (due to haematin alkali), and 

 a red precipitate, appearing green by reflected light, re-forms 

 which consists of earthy phosphates and haBmatin. This reaction is 

 called HELLER'S blood-test. If this precipitate is collected after a 

 time on a small filter, it may be used for the haemin test (see 

 page 79). If the precipitate contains only a little blood-coloring 

 matter with a larger quantity of earthy phosphates, then wash it 

 with dilute acetic acid, which dissolves the earthy phosphates, and 

 use the residue for the preparation of TEICHMANN'S haemin 

 crystals. If, on the contrary, the amount of phosphates is very 

 small, then first add a little CaCl 2 solution to the urine, heat to 

 boiling, and add simultaneously with the caustic potash some sodium- 

 phosphate solution. In the presence of only very small amounts of 

 blood, first make the urine very faintly alkaline with ammonia, add 

 tannic acid, acidify with acetic acid, and use the precipitate in the 

 preparation of the haemin crystals (STKUVE). 



Melanin. In the presence of melanotic cancers sometimes dark coloring 

 matters are eliminated with the urine. K. MORNER has isolated two coloring 

 matters from such a urine, of which one was soluble in warm 50-75$ acetic 

 acid and the other, on the contrary, was insoluble. The one seemed to be 

 phymatorusin (see page 324). Usually the urine does not contain any melanin, 

 but a chromogen of melanin, melanogen. In such cases the urine gives EISELT'S 

 reaction, becoming dark-colored with oxidizing agents such as cone, nitric- 

 acid, potassium bichromate, and sulphuric acid, as well as with free sulphuric 

 acid. Urine containing melanin or melanogen is colored black by ferric- 

 chloride solution (JAKSCH). 



BAUMSTARK found in a case of leprosy two characteristic coloring matters 

 in the urine, ' ' urorubrohaematin " and " urofnscohaematin," which, as their 

 names indicate, seem to stand in close relationship to the blood-coloring matters. 

 Urorubrohwmatin, CssHa^tNsFesOae , contains iron and shows an absorption- 

 band in front of D and one broader back of D. ID alkaline solution it shows 

 four bands, behind D, at E, beyond F t and behind G. It is not soluble either 

 in water, alcohol, ether, or chloroform. It gives a beautiful brownish-red 

 non-dichroitic liquid with alkalies. Urofuscoliamatin, CesHiosNsOaa , which 

 is free from iron shows no characteristic spectrum ; it dissolves in alkalies, pro- 

 ducing a brown color. 



Urorosein, so named by NENCKI. is a urinary coloring matter, occurring in 

 various diseases, which appears on the acidification of the urine with a mineral 

 acid, and which is taken up by shaking with amyl-alcohol. The solution shows 

 an absorption-band between D and E. Uroerythrin, which gives a rose-red 

 color to the urinary sediments especially in fevers, seems to occur also in urine 

 under physiological conditions. It has not been thoroughly studied. A 



