ESCAPE OF HEMOGLOBIN FROM BLOOD CELLS. 165 



albumin in the experiments made by Matthes is that which we assumed. 

 It must therefore be concluded that the blood-cells treated with 

 Hayem's solution do not dissolve in water because the mercuric 

 chloride with which they have combined prevents the escape of the 

 haemoglobin. The cause of this may be that the soluble substances, 

 e.g. the haemoglobin, form an insoluble combination with the mer- 

 curic chloride; it is sufficient, however, to assume that the limiting 

 membrane of the discoplasma becomes denser through the deposited 

 mercury salt and so prevents the diffusion of the blood coloring- 

 matter. Be this as it may, certainly all agencies which break up the 

 mercury combination will cause an immediate solution of the hae- 

 moglobin. The reason for this is that the discoplasma, which in the 

 living state hinders the diffusion of haemoglobin, has been killed 

 by the sublimate treatment, 



From this it is easily seen that the solution of the fixed blood 

 by means of pancreatin as it is described by Matthes, is not to be 

 regarded as a species of digestion. Every such ferment solution 

 contains enough albumin to explain the action according to our 

 view. I was able to confirm this by the experiment in which the 

 haemolytic action (observed by us also) of neutral pepsin and pan- 

 creatin solutions was exerted in like manner when the solution had 

 previously been heated to 95 C. for 1 hour. 



In conclusion it may be remarked that, after fixation with J% 

 mercuric chloride solution in physiological salt solution instead of 

 with Hayem's fluid, the blood-cells behaved in exactly similar fashion, 

 as was a priori to be expected. The control tests made at the same 

 time with normal blood gave negative results in all the experiments. 

 On the other hand with solanin, a substance which dissolves normal 

 blood even in enormous dilutions, haemolysis of fixed blood-cells 

 could not be effected even though large doses were employed. In this 

 substance the necessary albumin is wanting and the dead blood- 

 cells are no longer vulnerable to the action of the blood poison. 



To sum up, we may say that in the blood-cells hardened with 

 Hayem's solution it is merely the chemically bound r.iercuric chloride 

 which hinders the escape of the haemoglobin. All agents which are 

 capable of attracting this salt to themselves, i.e. to " de-harden " the 

 blood-cells, cause the immediate escape of haemoglobin. 



Hence, although the observations of Matthes are extremely inter- 

 esting in themselves, they possess no value for the doctrine of hae- 

 molysis. On the other hand it would seem as though they might 



