URINE. 489' 



Braconnot met with a case of blue urine passed by a girl of fif- 

 teen years of age, enjoying pretty good health, though subject to 

 stomach complaints.* During a paroxysm of pain in the stomach 

 she vomited and voided urine. Both liquids had so deep a blue 

 colour that they appeared almost black. The blue pigment 

 which this urine contained had neither taste nor smell. It was 

 in a state of very minute division, and had a deeper colour than 

 Prussian blue. When heated it gave out carbonate of ammonia 

 and an empyreumatic oil. It was slightly soluble in water and 

 in boiling alcohol. The alcohol assumed a green colour, and de- 

 posited on cooling a small quantity of very deep blue pigment, 

 almost crystalline. When the alcohol evaporated the blue pig- 

 ment remained, and dissolved in acids with the exception of a lit- 

 tle fatty matter. The blue pigment is soluble in all acids, even 

 the oxalic and gallic, and when so dissolved becomes red. When 

 a saturated solution of this colouring matter in dilute sulphuric 

 acid is evaporated, we obtain a carmine-red residue, which be- 

 comes brown when dissolved in water, but resumes its red colour 

 when the water is evaporated off. The blue matter is slightly 

 soluble in acetic acid. The solution is brownish-yellow, but 

 when the acid is driven off, the blue colouring matter is left un- 

 altered. When the red acid solutions are saturated with an al- 

 kali, the colouring matter precipitates with its original blue colour. 

 This blue matter is scarcely soluble in caustic potash, and not at 

 all in the carbonate of potash. 



The urine from which this blue matter had separated let fall 

 when heated an additional quantity of this blue matter of so deep 

 a shade that it appeared black, but possessed the properties of the 

 original blue pigment. Braconnot considers this blue sediment as 

 a salifiable base, and has distinguished it by the name ofcyanurm. 

 Marx made some experiments on a blue-coloured urine passed 

 by Dr Wollring at Gottingen.| He analyzed the sediment, and 

 states its constituents as follows : 



Blue colouring matter, , 29-09 

 Uric acid, . . 46-80 



Earthy phosphates, . 18-19 



Mucus, . . 5-92 



100- 



* Ann. de Chim. et de Phys. xxix. 252. f Schweigger's Jour, xlvii. 487. 



