CHEMICAL HAMS oF THK ANIMAL BOD1 



ronic acid (see p. 202). These compounds when d- 1 by 



hydrochloric acid or oxidising agei : - . ;i eolou: 



ter which is more or less red and may exlui um-t and 



strong purple tint. 1 Tin- pigment is inaolnbk in water, I. ut solu- 

 ble in either alcohol or chloroform, also when freshly prepai 

 ether 1'iit less so if it has been kept some time. A'lcoholi, 

 lions are ut' a reddish-violet colour ; etheieal solutions may 

 a x 1 "''*' 1 ' fluorescence, which on exposure to tin- air takes on a 

 reddish tinge. It is also soluble in hydro* -hlori, ;i n,l sulphuric 

 BCidB, giving bright iv.l or pink solutions, and in alkalis \ield- 

 ing yellow solutions. No absorption band* for this 

 have as yet been described and the whole subjeet n-.juii 

 investigation. 



A considerable number of red or reddish-purple pigment.- have 

 at different times been obtained and described urnl* 

 names as derived either from pathological urines when 

 voided, or from the spontaneous decompositions of or action of 

 mineral acids on different urines. The remarks which hav- 

 made on the indoxyl and skatoxyl pigments indicate a possibility 

 that they may all have a common origin and thus be closely re- 

 lated it' nut in many cases identical. In the absence of any 

 antee of the purity of the several coloured product their 



not having undergone some change during the operations in- 

 volved in their preparation, no authoritative statement \\ this 

 point can as yet be made. Indeed the whole subject of the 

 origin, nature, and relationships of urinary pigments is at pres- 

 ent in a state of considerable confu-imi and uncertaii.- 



The urinary pigments so far dealt with may be regarded as 

 either normal or pathological, or as resulting from the spontaneous 

 or artificial decomposition of urinary constituents which an- at the 

 outset colourless. In addition to these, other colouring substances 

 are not. infrequently observed, or colour-reactions obtained, in 

 urines passed after the admini.-tration of certain drugs or the 

 consumption of certain vegetable tissues. They are in many cases 

 not unimportant as leading at first sight to possibly 

 conclusions as to the presence in urine of pathologically iin]Krtant 

 pigments, e.g. of bile or blood. After the administration of rhu- 

 barb or senna, the urine may be yellow :i-h-\.-llo\v. d 



the presence of chrysophanic acid [<',,!! ( II I (OH) 

 similarly after the use of santonin ',.11,. <>.,). In such ( uses if 

 the urine is strongly alkaline it may be of a red colour; tl 

 changed to yellow on the addition of hydrochloric acid, and if it 



1 ntt,,, pfliignr's Arch, Bel. xxxili. (1884), S. f.l f, '/J. f. pkyiiol. 



H.I. MI (1888), s i.-in 



r further litorature of these rod pigment* Me Mmtr Abo 



lifrl. & / 



klin. Meil. ISXH, -tokvis (Piit.-M. .\i~' in Maly'i litrlcht. 1W9. 8. 468. 



