1864.] 



of the Cohmriiig Matter of the Blood. 



359 



of forming an emulsion. Wiien enough acetic acid has been added, the 

 acid ether rises charged with nearly the whole of the colourmg matter, 

 while the substance which caused the precipitate remains in the acid watery 

 layer below*. The acid ether solution shows in perfection the characteristic 

 spectrum fig. 3. When most of the acid is washed out the substance falls, 

 remaining in the ether near the common surface. If after removing the 

 wash-water a solution, even a weak one, of ammonia or carbonate of soda 

 be added, the colouring matter readily dissolves in the alkali. The spec- 

 trum of the transmitted light is quite different from that of scarlet cruorine, 

 and by no means so remarkable. It presents a single baud of absorption, 

 very obscurely divided into two, the centre of which nearly coincides with 

 the fixed line D, so that the band is decidedly less refrangible than the 

 pair of bands of scarlet cruorine. The relative proportion of the two parts 

 of the band is liable to vary. The presence of alcohol, perhaps even of 

 dissolved ether, seems to favour the first part, and an excess of caustic 

 alkali the second, the fluid at the same time becoming more decidedly 

 dichroitic. The blue end of the spectrum is at the same time absorbed. 

 The band of absorption is by no means so definite at its edges as those of 

 scarlet cruorine, and a far larger quantity of the substance is required to 

 develope it. 



This difference of spectra shows that the colouring matter (hsematin) 

 obtained by acids is a product of the decomposition, or rnetamorphosis of 

 some kind, of the original colouring matter. 



When hsematin is dissolved in alcohol containing acid, the spectrum 

 nearly agrees with that represented in fig. 3. 



12. Hsematin is capable of reduction and oxidation like cruorine. If 

 it be dissolved in a solution of ammonia or of carbonate of soda, and a little 

 of the iron salt already mentioned, or else of hydrosulphate of ammonia, be 

 added, a pair of very intense bands of absorption is immediately developed 

 (fig. 4). These bands are situated at about the same distance apart as 

 those of scarlet cruorine, and are no less sharp and distinctive. They are 

 a little more refrangible, a clear though narrow interval intervening between 

 the first of them and the line D. Tbey differ much from the bands of 

 cruorine in the relative strength of the first and second band. With cruo- 

 rine the second band appears almost as soon as the first, on increasing the 

 strength or thickness of the solution from zero onwards, and when both 

 bands are well developed, the second band is decidedly broader than the 

 first. With reduced hsematin, on the other hand, the first band is already 

 black and intense by the time the second begins to appear ; then both 

 bands increase, the first retaining its superiority until the two are on the 



* ]f I may judge from the results obtained with the precipitate given by acetic acid 

 and a neutral salt, a promising mode of separation of the proximate constituents of blood- 

 crystals would be to dissolve the crystals in glacial acetic acid and add ether, which pre- 

 cipitates a white albuminous substance, leaving the hsematin in solution. 



