QUANTITATIVE ESTIMATION OF BLOOD-PIGMENTS. 303 



From what has been said above about the absorption behavior, 

 the concentration and the extinction coefficient it follows that the quo- 



77" 



tient of the extinction coefficient measured at two different parts of 



E 



the spectrum, independently of the concentration, is a characteristic 

 constant for the respective pigments. According to HUFNER'S figures 

 this quotient for oxyhaemoglobin is 1.58, for haemoglobin 0.76, for 

 carbon-monoxide haemoglobin 1.10 and for methsemoglobin 1.19. BUT- 

 TERFIELD l who has made a thorough investigation on this, finds the 

 figure 1.58 for normal and pathological human blood as well as for 

 crystalline human, horse and ox oxyhaemoglobin. 



The quantity of each coloring-matter may be determined in a mixture 

 of two blood-coloring matters by this method; this is of special impor- 

 tance in the determination of the quantity of oxyhsemoglobin and 

 haemoglobin present in blood at the same time. 



In order to facilitate these determinations, HtJFNER 2 has worked 

 out tables which give the relation between the two pigments existing 

 in a solution containing oxyhaemoglobin and another pigment (haemo- 

 globin, methaemoglobin, or carbon-monoxide haemoglobin), and thus 

 allowing of the calculation of the absolute quantity of each pigment. 



Among the many apparati constructed for clinical purposes for the 

 quantitative estimation of haemoglobin, FLEISCHL'S hcemometer, which has 

 undergone numerous modifications, HENOCQUE'S hcematoscope, and 

 SAHLI'S hcemometer, are to be specially mentioned. In regard to these 

 apparati we must refer to larger hand-books and text-books on clinical 

 methods. 



Many other pigments are found besides the often-occurring haemoglobin 

 in the blood of invertebrates. In a few Arachnidse, Crustacea, Gasteropodae 

 and Cephalopoda? a body analogous to haemoglobin, containing copper, hcemo- 

 cyanin, has been found by FREDERICQ. By the taking up of loosely bound oxygen 

 this body is converted into blue oxyhcemocyanin, and by the escape of the oxygen 

 becomes colorless again. According to' HENZE 1 gram hsemocyanin combines 

 with about 0.4 cc. oxygen. It is crystalline and has the following composition: 

 C 53.66; H 7.33; N 16.09; S 0.86; Cu 0.38; 21.67 per cent. On hydrolytic 

 cleavage with hydrochloric acid HENZE found the following division of the nitro- 

 gen in hsemocyanin: Of the total nitrogen 5.78 per cent was split off as ammonia, 

 2.67 per cent as humus nitrogen, 27.65 per cent as diamino nitrogen, and 63.39 

 per cent as monamino nitrogen. He found no arginine in the cleavage products, 

 but could detect histidine, lysine, tyrosine, and glutamic acid. A coloring- 

 matter called chlorocruorin by LANKESTER is found in certain Chaatopodse. 

 HcBmerythrin, so called by KRUKENBERG but first observed by SCHWALBE. is 'a 

 red coloring-matter from certain Gephyrea. Besides hasmocyanin we find in the 

 blood of certain Crustacea the red coloring-matter tetronerythrin (HALLIBURTON), 

 which is also widely spread in the animal kingdom. Echinochrom, so named 



1 Zetischr. f. physiol. Chem./62. 



2 Arch. f. (Anat. u.) Physiol., 1900. 



