104 



Lately, instead of counting the red blood corpuscles their volume 

 percentage was used (by means of haematocrit and centrifugalisation) to 

 find the number of erythrocytes, which, as numerous comparative 



experiments have proved is -r^ 



As the viscosity of blood is chiefly due to the amount of blood 

 corpuscles contained in it, the measurement of the internal friction 

 also gives an idea of the degree of destruction, and series of figures 

 obtained from blood examinations on horses suffering from isolytic 

 haemolysis, piroplasmosis, or artificial anfemia demonstrate that the 

 viscosity of blood is subnormal and goes parallel with the volame 

 of red blood corpuscles. 



There is no doubt that physico-chemical researches on the serum 

 of animals showing haemolysis from the injection of haemolytic serum 

 would have l)rought forward results similar to those we observed in 

 piroplasmosis in horses, namely, alterations of specific gravity, electric 

 conductivity, depression of freezing jaoint, internal friction, capillarity, 

 etc., because the products of the destruction of erythrocytes circulating 

 in the plasma for a certain time influence the osmotic concentration and 

 the structure of the colloids of the serum. 



The main factor producing the second group of clinical systems is 

 the haemoglobin. 



Haemolysis means not only a diffusion of haemoglobin but also of 

 salts out of the stroma through the membrane of the red blood cor- 

 puscles. These three residues, stroma, haemoglobin, and salts have to be 

 eliminated out of the lilood. The organs which come in consideration 

 for this function are : 1, liver ; '1, kidneys ; 3, spleen ; 4, bone marrow. 



Erythrocjnes which have been killed by any haemolytic substance 

 are phagocytosed, and tiiose still containing haemoglobin are deposited 

 in the liver. The haemoglobin dissolved in the plasma is also kept 

 back and carried by the circulation. The haemoglobin is then decom- 

 posed : one part of the in-odacts which contains the iron (haemosiderine 

 iron-albumine) is either taken off by phagocytes and deposited in liver, 

 spleen, and bone marrow (Biondi*) or discharged in the urine. The 

 part free of iron is the basis of tlie bile pigments (bilirubine and bili- 

 verdin) which are sent partially into the duodenum, whilst the other 

 part after a further chemical i^rocess (bilirubine-urobiline) goes through 

 the kidneys into the urine. Such is the case already under normal 

 circumstances. (Several authoi's found in cases of haemolysis an in- 

 crease of bile pigmejits.t) 



When the accvimidation of haemoglobin and the production of bile 

 pigments has reached a certain supernormal degree, a greater or smaller 

 amount of bile passes over — by a mechanism, unknown at present — 

 into the blood (cholaemia). These (colloidal) pigments are absorbed by 

 the tissues and thus give rise to the symptom called icterus (conjunc- 

 tiva, mucosae). The presence of bile pigments in the blood is soon 



* Ziegler, Beitrase ISth Jau., 189.5 ; cit. Schmidt, Lubarsch-Ostertag, Ergebu. 3, 542, 1897. 

 t Oswald, Chem. Pathalog. Leipzig, 1907, 127. 



