Royal Society* 227 



little blue colouring matter, and it had a medicinal smell resembling 

 somewhat that of Valerian. In this state, without undergoing any 

 further material changes, the urine remained for many days. 



Examined with the microscope, the scum or pellicle on the sur- 

 face was found to consist of vibriones, innumerable animalcules, and 

 crystals of triple phosphate, with a great many fragments and gra- 

 nules of a deep and bright blue colour. 



A second sample of the same urine was therefore procured, taking 

 every precaution to avoid fallacy. Gradually the same changes en- 

 sued as in the first sample, and this likewise became blue. Having 

 thus ascertained that the changes observed were due to something 

 contained in the urine itself, the author next proceeded to set aside 

 in open vessels, a series of urines all from the same patient, noting 

 the alterations which occurred from day to day; these samples 

 underwent nearly similar changes ; but the quantity of blue colour- 

 ing matter and brown extractive gradually diminished, until at length 

 they were present in such small amount as to be visible only under 

 the microscope, and at last they entirely disappeared. 



The results obtained from an examination of the urine, the blue 

 colouring matter and the brown extractive, are then given by the 

 author ; they are as follow : — 



The urine. — The urine of the second sample at the time of analysis, 

 when shaken, had a dark, greenish-brown colour ; but on standing 

 at rest for some time, the colouring matter fell to the bottom, form- 

 ing bluish- green flocculi, while the supernatant liquid was of a 

 deep wine-red colour. The bottle was set aside corked, for ten days, 

 at the end of which time the bluish-green precipitate had entirely 

 disappeared ; but on removing the cork, and allowing free access of 

 air for some time, the coloured deposit was again produced. This 

 was washed with water, drenched with hydrochloric acid, and finally 

 dried ; by this means was obtained a rich blue powder possessing all 

 the chemical characters and properties of indigo. 



The urine that was filtered off from the above precipitate was 

 allowed to evaporate spontaneously, by which means it yielded an 

 additional quantity of indigo, which adhered in the form of very 

 small flakes to the sides of the dish. It also gave a rather large 

 proportion of a deliquescent brown colouring matter, which was 

 treated, first with alcohol, and then with water. 



The alcohol acquired a deep brownish-red colour, and the water a 

 dark brownish- green. Both of these solutions were evaporated at a 

 temperature of 160° Fahr. The alcoholic solution furnished a rich 

 brown extractive which was soluble in water, but not in dilute acids, 

 and nitric acid did not produce that play of colours which is cha- 

 racteristic of bile pigment ; nor did the precipitate formed with basic 

 acetate of lead furnish a purple liquid with alcohol and free acid. A 

 strong solution of potash dissolved the extractive and yielded a deep 

 blood-red fluid, which was rendered green and opalescent by boiling. 

 These reactions show that the brown pigment was somewhat like 

 hsematine in its chemical manifestations. 



While the aqueous solution of the brown matter was undergoing 

 Q2 



