328 THE SECRETIONS: 



dysuria and vesical calculus, and subsequently from typhus 

 fever. 



Marcet, Prout, Braconnot, Babington, Gamier, Spangeberg, 

 and others, have observed blue and black urine. I have re- 

 lated a case in which the urine deposited a blue sediment, in 

 page 274. 



I have made an examination of the urine passed by a man 

 at Grafenberg, who had spent many years in the East Indies, 

 and returned to Europe for the benefit of his health. It had 

 a strong ammoniacal odour, was of a clear blue colour, and de- 

 posited a somewhat copious dark blue sediment, which ap- 

 peared, from a microscopic examination, to consist of very fine 

 amorphous matter (on which the blue colour was dependent) 

 and a few crystals of ammoniaco-magnesian phosphate. On 

 treating a portion of the washed and dried sedim'ent with caustic 

 potash the colour did not disappear; hence it was not de- 

 pendent on the presence of iodide of starch or prussian blue. 

 Dilute organic acids and hydrochloric acid neither dissolved it 

 nor destroyed its colour ; but on digesting it in nitric acid, the 

 tint changed from blue to yellow. Digested in concentrated 

 sulphuric acid, it dissolved, forming a solution of an indigo 

 colour. On warming a portion of the sediment on platinum 

 foil, it first evolved an urinous odour, and subsequently vola- 

 tilized, going off in deep violet-coloured vapour. The most 

 convincing proof that the blue tint was due to indigo, was that 

 on warming a portion of the sediment with dilute alcohol to 

 which grape sugar and potash had been added, the fluid lost 

 its blue tint, and assumed a yellowish red colour, which, on 

 shaking, was converted into an intense blood-red, and then 

 rapidly into a green. On allowing it to rest the green tint 

 disappeared, and the fluid assumed a yellowish-red colour. All 

 these phenomena led to the conclusion that the colouring mat- 

 ter was indigo. I have since heard that specimens of the same 

 urine were sent to Bouchardat, Liebig, and Prout, who coin- 

 cide in the opinion that the pigment was not indigo, but a dis- 

 tinct organic compound. No indigo, or indeed medicine of 

 any sort had been recently taken by the patient. 



Dulk 1 has observed and analysed black urine passed by a per- 

 son suffering from derangement of the liver and portal system. 



1 Archiv der Pharmacie, vol. 18, p. 159. 



