< 1IK.MICAL BASIS OF Till! ANIMAL BODY, 



detect tin-in. If not they may be obtained in a more com-ei.- 

 residue, which has been largely freed by Hu|>]nTt's method from 

 other colouring matters which inti-rtn. with tin- test. The tluiil is 

 precipitated by lime-water and carbon dioxide. Tin- compound ..i" 

 lime and liilirnl.in is then collected .,n a tiller, \\a-hed and te-t,-d in 

 situ by the addition of fuming nitric acid; ,,r it may !> boiled in a 

 te>t-tube with a little alcohol acidulated with sulphuric acid; the pre- 

 cipitate l,.-.-- its colour and the apernatant alcohol turns to a brilliant 



-,'i-een. The following i- al-o a relialde tot as applied to urine. 1 To 

 I'll ,.r .'!( c.c. of urine add ." to 1(1 c.c. of a Oration ol xinr a 

 (!:.">). Tin- can-.-- a \ oliiminous precipitate of \, ile-pi<rmeiit>. espe- 

 cially if the acid reaction he >ome\\hat redu.-ed l>y tin- simultaneous 

 addition of a little sodium carbonate. The precipitate is co] ; 

 (.n a filter, washed with water, and dissolved in a little ammonia. If 

 bile-pigments are present tbe solution i- u-ually tliior.--c.-nt, and on 

 standing, if not at once, shows the absorption hands characteristic 

 of bilicyanin. (See below.) For further details ( .f other methods 

 con-ult some special work. 9 



The accurate quantitative determination of bilirubin. as of 

 other bile. and also of urinary-pigments is only possible l.y 

 spectrophotometrio methods. These have l)ecn already brietly 

 described on p. 224. The requisite constants for the application 

 of the method in the case of each pigment are given in tin- litera- 

 tim 1 1 noted below. 3 



r.ilirubin, while it exhibits no distinct absorption bands, is 

 < hara< tdisrd by u powerful absorption of the violet end of the 

 spectrum. 



1'. Biliverdin. ('...H.^A- 



This is, as aln-ady stated, the first product of the oxidation of 



bilirubin. It gives the characteristic colour t<> tin- bile of lu-rbi- 



vma. probably accounts for tbe colour of biliary vomit in caini- 



\..ni iinaii), i- p<.--il>ly found in tin- urine in icterus, has l>een 



stated to occur in the edges of the placenta in pregnant animals * 



hitches , while on the other hand it occur- in m.-iv trace- in gall- 



stones whether of man or other animals. It 1ms also M8D 



:l>ed as occurring in egg-shells 6 and the integuinciits of 



M invertebrates. 



Preparation. An impure product may be obtained a- follows 

 from herbivorous bile. After the removal of mucin (p. 76). barium 



See Abst. in Malr's Jahretb. 1992, S. 226. 



- N.-ul.aii.T ti. V. >,.]. Amtl. <1. //<irnt, 1890, 8. 321 et teq. 



Vioronlt, !>>> i/n"nt. SftetnUutalyM u. t. w. Tubingen, 1876, 8. 76. '/J. f. 



13), S. |t,o. |M v (1S74). S. 21, 399. V<m\a, Arch. f. erp. Patkol. 



M. xi. (is: 



* Ktti. s,-. MaU's ./<i/,/> s'.. 1871,8 MS, 



' l.i.-K.-rmaim. /'-. //. J. <!,. '/.//. I'.-l M. (l">l. S. f.Ol. 

 Vtrhnndi. ,1. /,/, i/.vil.-w. ,1. (1. It '>'. tu U .. \MI. (1883), a 109. 



Krukenbefg, Ctnlralb./. !. <"/ H'i. 1883, 8. 785. 



