124 REPORT — 1861. 



strange to say, when tlie patient was least cared for. He urged the necessity of 

 feeding and supporting the patients at their weakest hour, so as to tide them over 

 a critical period. 



On the Bdative and Siiecial Aiiplications of Fat and Sugar as Besinratory 

 Food. By Dr. Thomas HatdejST. 



On the Occurrence of Indir/o in Purulent Discharges. 

 By Dr. W. Bieb Hekapath, F.R.S. 

 This paper was on the occurrence of indigo in purulent discharges, in which, after 

 alluding to obser\-atious made by him to the members of the Medical Association 

 on two instances which had occurred in his practice, in which he had foimd indigo 

 in the mine of indiriduals suifering from renal disease, he said that since that period 

 they had been instructed by Heller, Schunck, Vu-chow, and others that m'ine, even 

 in the healthy state, contained a substance fi.-om which an indigo-blue pigment 

 might be obtained in traces or excessively small quantities ; and liletzinsky had 

 shown them that the mine of the horse and the cow contained a comparatively 

 large quantitj^ of that pigment-forming substance. It was remarkable, however, that 

 indigo very rarely appeared to be eliminated directly from the body in its markedly 

 blue colour. On the contrary, it was thrown ofl' rather in the colourless form, or 

 as a lio-ht yellow substance, which, upon treatment with acids, split up into three 

 other substances, two pigments, named m-oglancine or indigo blue, urrhodine or 

 indigo red ; whilst a saccharine substance was also separated in a notable quantity, 

 — thus proving that indican or uroxanthiue is a glucoside. The colouring produced 

 by fermentation, oxidation, &c., was alluded to, and the author remarked that in 

 the indigo plant it would be recollected the colom-ing-material did not exist ready 

 formed, but that it required a peculiar process of fermentation and oxidation, to be 

 earned on iu the expressed juices of the plant during a considerable period, in 

 order to obtain that valuable blue in any quantity. The occm-rence of the vege- 

 table product, indigo, in the fluids eliminated from the human body had been con- 

 sidered an instance of the deterioration of the animal elements, as remarkable as 

 the presence of grape sugar in the blood. Sec, of diabetic patients ; but it was now 

 known that there were numerous proximate principles which, though usually 

 obtained from the vegetable kingdom, were common to both the animal and 

 veo'etable worlds. Pathologists and physiological chemists were tolerably weU 

 aoi-eed that the source of the indigo-forming substance in the animal economy 

 mioht probably be due to destruction of some of the proteine compounds, and more 

 especially hrematosin, the well-known coloming-matter of the blood-globules; for 

 they invariablj' found that the blue pigment predominated in those diseases in 

 which great destruction of blood-pigment occun-ed, as in phthisis, Bright's disease, 

 scarlatina, and such like diseases. Dr. Herapath cited a case in which pus or the 

 liquor pmis had been sho^m to contain bluepigment, and which he believed was the 

 first instance recorded of that character. The subject of the case was a coachman, 

 and had been under the author's care for phlegmonous erysipelas of the leg, which 

 occasioned extensive vesication, and ultimately sloughing of the integuments, from 

 which woimds large quantities of serum and pus exuded. The spirit lotions em- 

 ploj-ed in the treatment became rapidly blue in colour, and all the bed-clothes 

 were similarly stained blue on exposure to the air. Some of the blue-coloured 

 spirituous solution, set aside in a corked bottle, became shortly discoloured ; but on 

 ao-ain exposing to an-, its blue colour returned from the influence of oxygen on an 

 oxidizable material. Other agent.s, as chlorine, chlorinated lime, destroyed the blue 

 colour, as they would have done in preparations of indigo. The blue-coloured 

 material was separated on a filter, dissolved in a solution of potassa, when de- 

 oxidized by sugar, and again separated from impmities by filtering, from which 

 fluid the indigo was deposited by renewed exposm-e to atmospheric oxygen ; some 

 of this pigment, fm-ther purified by washing and diying, gave blue-coloured hexa- 

 gonal prisms on being cautiously sublimed by following Dr. Guy's directions, and 

 when examined in the microscope had aU the appearances of sublimed indigo, 

 which the action of other chemical tests confirmed. The som-ce of this pigment 



