1164 
horse blood and that only a long-continued standing produced a just 
perceptible turbidity with dilntions of horse-serum *). 
LEBLANC’s *) results also are in favour of the antigenic property 
of haemoglobin, for he found, that the haemoglobin is carried down 
with the precipitate produced by precipitin-serum. 
As I intend further to pursue this investigation I shall perhaps 
come back to this point later and also describe more fully the 
results which are only shortly sammarised lere. 
In my experiments I used for the immunisation of rabbits crystallised horse- 
haemoglobin, prepared in the same manner as described by Ipe and Demesgs; i.e. 
defribinated horse blood was centrifugalised, the sediment washed five times and 
again centrifugalised, the bloodcorpuscles dissolved in etherised water of double 
the volume of the original blood, kept in the icechest for one or two days, and 
during this time repeatedly shaken, and finally decanted to get rid of any sediment 
which might eventuaily still be present. In order to free it from stromata and 
globulin, it was mixed with an equal volume of saturated ammonium sulphate 
solution, the precipitate filtered off through a folded filter. To the clear filtrate 
ammonium-sulphate crystals were added until the haemoglobin (standing in the 
cold) was precipitated, the filtered precipitate washed with ammonium sulphate 
solution, suspended or dissolved in water, some ether added and the mixture 
dialysed. Finally 10/, of sodium chloride was added. 
In the test tube experiments I took solutions which had been prepared from 
very well washed blood corpuscles with water and ether, the water amounting 
to twice the blood volume. The solutions were completely freed from susupended 
matter by filtration through an asbestos filter. In the case of horseblood, moreover, 
the solution of crystallised haemoglobin was used. 
The tests for specificity gave the following result. 
Technique of the experiments: The 5°/) haemoglobin solution was diluted to 1 : 
500 and 0.2 ce. of this taken. To this were added 3 capillary drops of 0.04 ce. 
each, of immune serum and left to stand one hour at room temperature and the 
reading taken. Horse-serum diluted 500 times. 
Tests were also made with all solutions in dilutions of 1 : 100 and 1 : 2.500. 
They are not given in detail because they agree with the experiments of the 1: 
500 dilution. 
Haemoglobin solutions. serum 
~ wv | = | 
ag Sie Woe SAD ern EEN oh 
cS i | 3 2 o 
BA Sais) Se ENE 
Gg ee RAG ap dan 0 of +] oo 0 
1) A solution of the horse haemoglobin reacted in the same manner against an 
ordinary anti-horse precipitin. 
2) Ipe. le. p. 263. 
