THE BLOOD. 83 



The amount of haemoglobin is expressed as percentage of the 

 physiological amount of haemoglobin. 



Many other coloring matters are found besides the often-occurring haemo- 

 globin in the blood of in vertebra. In a few arachnidae, Crustacea, gasteropodae, 

 and cephalopodae a body analogous to haemoglobin containing copper, hcemo- 

 cyanin, has been found. By the taking up of loosely-bound oxygen this body 

 is converted into blue oxyhwmocyaiiin (P. BERT, FREDERICQ, KRUKENBERG, 

 M.\cMuNN), and by the escape of the oxygen becomes colorless again. A 

 coloring matter called chlorocruorin by LANKESTER is found in certain 

 chaetopodae. Hwmerythrin, so called by KRUKENBERG but first observed by 

 SCHWALBE, is a red coloring matter from a few gephyrea. Besides haemo- 

 cyanin we find in the blood of certain Crustacea the red coloring matter 

 tetronerythrin (HALLIBURTON), which is also widely spread in the animal 

 kingdom. EcJiinochrom, so named by MAcMuNN, is a brown coloring matter 

 occurring in the perivisceral fluid of a variety of echinoderms. 



The quantitative constitution of the red blood-corpuscles is 

 difficult to determine and we have hardly any sufficiently trust- 

 worthy analyses of them. The amount of water varies in different 

 varieties of blood between 570-630 p. m., with a proportional 

 amount, 430-370 p. m., of solids. In the blood of mammalia the 

 chief mass (about nine tenths) of the dried substance consists of 

 haemoglobin. 



According to the analyses of HOPPE-SEYLER and his pupils, the 

 red corpuscles contain in 1000 parts of the dried substance: 



Of special interest is the varying proportion of the haemo- 

 globin to the albumin in the nucleated and in the non-nucleated 

 blood-corpuscles. These last are much richer in haemoglobin and 

 poorer in albumin than the others. The amount of mineral bodies, 

 as far as they have been determined, in the moist corpuscles is 4.8- 

 8.9 p. m. The chief mass consists of potassium, phosphoric acid, 

 and chlorine. The blood-corpuscles of ox-blood contain, accord- 

 ing to BUNGE, more sodium and chlorine than phosphoric acid and 

 potassium. The blood-corpuscles of the pig and horse contain no 

 sodium (BUNGE). Human-blood corpuscles contain, according to 

 WANACH, about five times as much potassium as sodium, on an 

 average 3.99 p. m. potassium and 0.75 p. m. sodium. 



