CHEMICAL BASIS OF THK ANIMAL lioDV. 



have been t-iiiployed, 1 of which the most recent, said to \ j. M 

 of crystals from ea'-h 1 litre of blood, is as follows. 2 T.< 

 volume lit' defihrinat'-d ami -trained blood add fuir volumes of 

 glacial acetic acid previously warmed to 80. As soon as the 

 temperature of tin- mixture has fallen to 55 60, it must be 

 auain warmed to 80. On cooling ami standing for 1U ll' hours 

 ils separate out; the supernatant liquid is then removed l.y 

 a syphon. the crystals are washed with water repeatedly i, v d-- 

 cantation in a tall glass cylinder and are finally n.lleeted oil a 

 filter and washed with water, alcohol, and ether. 



Tim successful preparation of hainin crystals from minute 

 quantities of ha-imi^lobiu or metlia-moglohin is of the gr- 

 importance for medico-legal purposes, since they suffice, even in 

 the absence of all other confirmatory evidence, to establish the 

 nature of the material used in their preparation. In the detection 

 of 1)1 md-stains it is usual first to examine with a spectroscope an 

 aqueous solution of the colouring matter if it can lie obtained, for 

 the characteristic absorption bands of oxy-memoglohin or nietli;em.i- 

 globin. In old stains the hemoglobin is frequently decomposed, 

 in which case it is insoluble in water, and alkaline extracts must 

 be made and examined for the spectra characteristic of ha-matin 

 The residues from the spectroscopic examination are lastly u-ed 

 to prepare hsemin crystals, in final confirmation of the evidence 

 previously obtained. 3 



has already been made (see p. 234) to some work on liii'inin 

 and huMiiatin which assigns to these substances a eompo>it imi and 

 relationship very different from those usually accepted, and further 

 puts the relationship of the colouring matter of blond to the hile- 

 pigmentfl in a new light. 4 "With the preliminary rautinii that the>r 

 \ii-\vs are not as yet generally aecfjited and reijuire continuation, tln-y 

 may be briefly dealt with here. Using aniyl-ulcohol in the pri-para- 

 tioii of h.-emiii rrv>t;ds it is stated that the crystals have the following 

 .onipo>iti.,n (C M H,oN 4 FeO, . HC1)C 6 H,. OH. Th.- gr..uj. II N, 

 it regarded as the true ha-min. Teiohnuuui^ oryttala ooniuting 



of C 88 H $0 N 4 Fe0 8 . HC1. When thr crystals thus pivpaiv,! are d.-.-oin- 

 [...-. d by caustic alkalis as in the ordinary method for |.iv]iariiiK r h:-ina 

 tin from tin-in, the heemin is Hii|.p.i>ed to take up one m-.b-i-uli- of 

 watrr and yi.'M ba-matin C,,H M N 4 FeO v I'.y treating this li:ematin 

 with strong sulphuric acid, it loses its iron and uniting with OS 

 yield- li:ematoj>or]iliyrin or iron-free luematin, C a ,H M N 4 Oj, \\lncli i- 



M Gamgee, Physiol. Chun. Vol. i. p. 116, or H..p|M-Scyler, Pkytiol. 

 1 Anil :. I*-:?. S. -JH. 



:;ilfi-j.-w. .In. ,1. runs. ,>h Ht.-chftn. Getfll. 1885. See Ahtr. in Her. d d 

 ,h.m. H.srll. xvni. M.l (ls".-.i. K'.-f. S. 232. 



For detail* see Hoppe-Seyler. lor. fit. S. 529. Gamgee, /<*. c,t j. i'l.. 

 \Iiiini, The gnectroscoiH! in medectne, 1883. pp. l:w U- 



ndd ii Sieber, Btr. <l .1 //. IM. xvn. (1H4). S : 



, . 



S. 392, Arch. f. txp. I>,,th. . I'lm.m. IM. win (1884), & 4>l. IM. XX. (1886), 8. 

 Bd. x\n (1888), S 4.'!0 NViu-ki n. l{..t-!i\ .'/ "><ithf. f. Chem. ' 



also Hoppe-Sevl.T in advrrs- . ritic-imn. /;.-. d.d.chem. GtMU. Bd XMII 

 (1885), S. 601, Zt.f. phytio). Chem. Bd. X (1886), S. 331. 



