212 



Dr. C. A. MacMunn. Researches into the [Dec. 16, 



The pigment was slightly soluble in ether and in benzol, but insoluble 

 in bisulphide of carbon. 



Hydrochloric acid and water dissolved the pigment completely, and a 

 different spectrum was then seen (Chart I, sp. 11). 



Strong sulphuric acid dissolved the pigment, forming a red solution, 

 giving sp. 12, Chart I. 



Permanganate of potassium did not seem to affect the spectrum, but 

 peroxide of hydrogen seemed to remove the feeble bands, leaving a 

 shadow from wave-length 584 to 567 and a band, <%, wave-length 507 

 to 482. 



Sulphurous acid made the alcoholic solution lighter in colour, and 

 gave in deep layer almost the same spectrum as with sulphuric and 

 hydrochloric acids ; and in a thinner layer, the band at F was the 

 same as before its addition. Hyposulphite of sodium did not affect the 

 spectrum. 



When the alcoholic solution was treated with sodium amalgam* its 

 reddish-brown colour changed to pale yellow after fourteen hours' 

 action, and it then gave sp. 13, Chart I. When this yellow fluid was 

 cautiously neutralised, and then slightly acidified with hydrochloric 

 acid, it became redder in colour and then gave sp. 14, Chart I, in a 

 suitable depth. 



When the fluid treated by sodium amalgam, and subsequently hydro- 

 chloric acid, was treated by permanganate of potassium, the band at F 

 was made fainter, and did not appear to be replaced by another when 

 caustic soda was added. 



This pigment was darker brown than febrile urobilin, which has a 

 reddish-brown colour, and it was evidently nearer to acid hsematin than 

 the latter pigment. Its affinity to the latter pigment was shown by 

 the way in which its band at F was affected by caustic soda, but by 

 the way in which that band was affected by ammonia it was seen to be 

 different. 



By the action of zinc and sulphuric acid on acid haematin, I have 

 succeeded in obtaining the same pigment (as will be described further 

 on), and the solutions of the artificially prepared pigment gave the 

 same spectra as those of this one, band for band, and the spectra of 

 its various solutions were altered in the same manner as those of the 

 present one by reagents. It would therefore appear that the various 

 bands seen in solutions of urohsematin are all due to one pigment, and 

 not to the presence of impurities. 



Urobilin, from the Urine of a case of Pleurisy, probably due to Tuber- 

 culosis. — There was but slight effusion into the pleural cavities ; the 

 temperature of the patient was 101° F. The urine was reddish-yellow 

 in colour, contained neither bile or blood, and gave a black band at F, 



* Cf. the action of sodium amalgam on Lsematoin, infra. 



