329 



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 v/ater, 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 

 hseraatin in its chemical manifestations. 



While the aqueous solution of the brown matter was undergoing 

 evaporation, it gave a further supply of indigo, which was formed 

 most freely at the edge of the liquid. The residue was made black 

 by concentrated sulphuric acid and deep brown by potash. 



The blue colouring matter. — Of two samples of this in a dry state, 

 mixed with a large quantity of earthy phosphates, vibriones, mucus, 

 and epithelium, one gave a dark brown solution with concentrated 

 sulphuric acid, and the other a dirty blue. Both of these solutions 

 were decomposed by water, furnishing in the former case a dark 

 brown deposit, and in the latter a dirty green. In most of their 

 other reactions, hov/ever, they presented the characters of indigo ; 

 and it is especially deserving of notice, that they were reduced by 

 lime and sugar, giving a liquid from which hydrochloric acid threw 

 down a greenish-blue precipitate. 



The cause of concentrated sulphuric acid giving with one of these 

 samples a brown solution, and with the other only a dirty blue, was, 

 the author considers, mainly owing to the large quantity of animal 

 matter with which the specimens were contaminated ; the acid, from 

 its charring eff^ect on this, would produce a brown or blackish solu- 

 tion, thus obscuring the colour of the solution of indigo. 



The brown extractive. — The brown extractive yielded nearly the 

 same results as on its first analysis, and the aqueous solution fur- 

 nished a few blue flocculi. A portion of the alcoholic extract was 

 heated with Liq. Potassse for the purpose of ascertaining whether it 

 contained leucine, and the product, on being treated Mdth hydro- 

 chloric acid, gave oiF a powerful odour, which was somewhat like 

 valerianic acid; but the result was too doubtful to be of much value. 

 The author had already referred to the peculiar smell of Valerian 

 emitted by the extractive of more than one of the samples. He con- 

 siders that the clearest and most positive evidence was thus obtained 

 that the blue colouring matter in this case was indigo. 



It was not very long after the occurrence of the first case of blue 

 urine that numerous other instances fell under the author's observa- 

 tion. The urines of all these cases underwent very nearly the same 

 changes as in the first ; in some, the quantity of blue colouring mat- 



