CHEMICAL BASIS OF THK ANIMAL I'.oDV. 



1nr m<i tin. 1 To observe the spectrum of this substance a 

 slice of tissue, such as that of the In-art, is sijuee/ed in a coin- 

 pressorium until sufficiently thin to transmit lk:ht. It i- then 

 examine. 1 with a mierospectroscope under strong illumination. 

 Or, on the other liand, the tissue may be treated with excess of 

 ether under whose intluciice an aqueous juice is extruded in 

 which tin- niyiiha-matin is in solution. Speaking generally, for 

 tin- appearances vary slightly according to the source ot tip 

 nn-nt. niyohii'iuatm yields a four-banded absorption spectrum. 

 Tin- first band lies close to 1), but towards the red end of the 

 spectrum. The next two bands are situated close together about 

 midway between D and E. The remaining band lies in tl 

 gion between E and b. Solutions of myohtematin an- when weak 

 of a ivddish-yellow colour, but if strong they an- pure red. I',\ 

 tin- action of warm alcohol containing a little sulphuric acid a 

 spectrum is obtained closely similar to that of ha-matin in acid 

 solution, and by the use of concentrated sulphuric acid a sul>- 

 stauce is produced which in both acid and alkaline solutions shows 

 bands similar to those of haematoporphyrin in the same si-lvi-nts. 

 Under certain conditions myohaematin becomes ' modified ' and now 

 yields two bands similar to those of ha-rnochromogen, but situated 

 nearer the violet end of the spectrum. 



The conclusions drawn from the above spectroscopic facts have, 

 been the subject of some controversy and adverse criticism, the 

 appearances being regarded as due not to a specific pigment, but 

 rather to haBmochromogen or mixtures of other products of the 

 decomposition of haemoglobin. 2 



11. Haemin. C^Hu^FeO, . HC1. (Haiinatin-hydrochloride, 

 or Teichmann's crystals.) 



These crystals may be readily obtained for microscopic ex- 

 amination by heating a drop of fresh blood on a glass-slide under 



FlO. 38. H.EM IN CRYSTALS FROM A DROP OF BLOOD. (Kuhn.) 



a cover-slip with a little glacial acetic arid. 3 In the case of 

 blood which has been dried, as in an old blood-clot or stain, the 



i MacMunn, Phil. Tram. It. i. 1886, p. 267, .rt. of Pkytiol. Vol. rill. (1887), 



i. :.i 



VT. '/A. f. i.f,*nJ. ('/< 15.1 xiii (!--''). S lin II, ,,,,- /. Bd. 



Xiv. (is'.in) S UK, K,-r fi.lv oe MacMunn. /'/./. MII S :. \n :28. 

 Tei.liiniu.n. Xt. f. rat. Kd. IM. in ( l:i). S. 375, Bd. Till. S. 141. 



