1167 
reaction of the alcoholic organ-extracts with the heterogenetic im- 
mune serum). 
It is evidently difficult to explain these results as it would seem 
as if specific immune bodies against one substance are formed by 
the injection of another. 
In my experiments, which were performed for the greater part 
without my having knowledge of the publications of Sorprrar and 
his coworkers, I obtained results that agree with their observations 
in main points, as I also found that the alcoholic extracts (and 
the ether-extracts) of a horse's kidney — though in vitro their 
capacity of combination is very great — do not bring about any 
or any appreciable formation of antibodes. However, further exami- 
nation induced me to give a modified explanation of this matter. 
In my experiments preparations of horse’s kidney were injected 
into rabbits. In one of these the procedure was as follows’): 
The kidneys were twice ground finely then sifted through a course-mesh-, and 
through a fine-mesh-sieve, emulsified with three times their volume of 0.9 per 
cent salt solution, placed in the ice-chest for 24 hours, being shaken repeatedly, 
and finally percolated (I). The turbid extract was digested with six times the 
volume of 95°/, alcohol during two days at room temperature, subsequently 
after filtration digested once more for 24 hours with 1 vol. of alcohol and the 
insoluble precipitate was taken up in 0.9 per cent salt solution (Il). A third 
portion was prepared like II, but here the substance that was obtained by 
evaporating the alcoholic extracts to dryness, was emulsified in 0.9 per cent salt 
solution, and was added to the suspension of the first precipitate (III). A fourth 
portion was digested similarly as to II with alcohol at room-temperature, and then 
the precipitate, obtained after filtration, was boiled for half an hour with one volume 
of alcohol and the insoluble part was suspended 0.9 per cent salt solution (IV) 
and finally the aqueous extract or the suspension was heated for half an hour in 
boiling water (V). 
All the suspensions were brought to the original volume of the extract, and 
0.25 ¥/, phenol was added. 
The following table shows the hemolytic action of rabbit’s sera, after 
two intraperitioneal injections (at an interval of a week) of the five 
extracts described above. The amount of every injection was about 
equal to 1 grm of kidney-substance; allowance should here be made 
to the fact that in percolating a large portion of the kidney-substance 
is left behind. 
The dilution of the sera was 1: 250; 0.5 ee. of this dilution 
is added 0.5 ec. of guinea pig complement 1:10 and 0.05 °/, 
sheep’s blood. 
') The subject will be discussed at length elsewhere. 
