102 



On the other hand, it must not be forgotten that quantitatively a 

 reduction of a haemolytic substance does not mean a direct proportional 

 decrease of its blood dissolving effect, as experiments of Cernovodeann 

 and Henri* witli serum and myself* witli saponine have proved. 



The diminution of haemolysis is at first very rapid and becomes 

 slower and slower as tlie haemoh'tically active substance decreases. 

 Tlierefore an equal quantitative reduction (for instance to the half) of 

 two sera of different haemolytic strengtli involves not a proportional 

 reduction (to one-half) of the effect of each on the same quantity of red 

 blood corpuscles, and the liaemolytic result of a mixture of the two 

 lialves of these sera need not he tlie matliematical average of the 

 individual effects. 



I am not able to say which of the above given possible explanations 

 holds good, biit certainly they both might be applicable. It is, of course, 

 not permissil)Ie to draw conclusions from the calculated mixture index 

 with regard to whether a serum mixture will produce haemolysis in 

 A'ivo. 



(Compare indices and results of injections of mixtures 1, 2, and 4.) 



III.— CLINICAL SYMPTOMS OF HAEMOLYSIS. 



The chief symptoms can be forecasted if it is kept in mind 



(1) what is the function of the living erythrocytes 



(2) ^\hat happens with them, when they are dead 

 We record, therefore, 



(a) symptoms due to the deficiency of reiL blood cells ; 



(b) symptons due to the elimination of the destroyed erytlirocytes. 



Naturally the symptoms mentioned under (a) appear first ; not 

 immediately following the injunction of the destructive serum, but 

 after a certain incubation. This is sometimes, after intrajugular injec- 

 tion, very short — in a few cases only about five minutes, in others a few 

 houT's ; it is longer, according to the resorption of the serum, after 

 subcutaneous injection, varying from 1-3 days. After this time the 

 decrease of the number of erytlirocytes and icterus are the most striking 

 symptoms, whilst the predominant xahenomena which follow immedi- 

 ately an intravenous serum injection are mostly troubles of respiration 

 and heart action. Under normal conditions the organism requii'es a 

 certain number of erythrocytes which are the carriers of a defined 

 amount of oxygen from the lungs to the tissues which is wanted by the 

 latter. As the frequency of pulse and respiration largely depends on 

 the extent or intensity of oxygen metabolism in the cells, a numerical 

 decrease of red blood corpuscles, as it happens after haemolysis, con- 

 sefiuently emphasises itself by acceleration of respiration and heart 

 action, the haemaglobine dissolved in the jjlasma being unable to 

 transmit oxygen. Both s,ym]ptoms sometimes take place very soon after 

 intrajugular injection of isolytic serum. In such instances the horse 



*Loco cit. 



