As the standard-solution was frothing very much, derrid might 
belong to the saponins and as such cayse laking of the blood. 
LH ifect on blood. 
Derrid was added to a solution of rabbits blood and the spectra 
were observed. From this it appeared that the normal oxy haemo- 
globin-spectrum was unchanged; when nitris amylieus was added 
the methaemoglobin-spectrum showed itself and when it was reduced 
with Sroke’s solution, the haemoglobin-band appeared. A bottle with 
blood-solution, quite full and well corked, was put aside after derrid 
had been added and after the presence of oxyhaemoglobin-bands had 
been ascertained. After more than 36 hours haemoglobin had formed, 
which was apparent from the spectrum, whereas after shaking the 
bottle both the oxyhaemoglobin-bands reappeared. So this proves that 
derrid does not change the power of baemoglobin to easily take up and 
give up oxygen. 
A series of experiments on laking was made. 
|. The blood of the minnow that died during the first experiment 
was received in a physiological salt solution; no laking showed itself here. 
2. Kel’s blood was defibrinated, washed and the standard solution was 
added to it (per ec. 0,1 m.g. derrid and 0,08 cc. ale. abs.); the “normal 
fluid” was a corresponding alcohol solution. By addition of NaCl’) 
both solutions were made isotonic to the blood. In each of a row of 
test-tubes was put 1 ec. blood besides increasing quantities of derrid 
and aleobol, in such a way that each tube contained an equal quan- 
tity of aleohol and ce. fluid, so that only the quantity of derrid varied. 
The quantity of derrid was such that effect on the whole animal 
could be expected with absolute certainty ; a tube with blood and 
salt-solution was always at hand for the sake of comparison. 
After 12 hours neither laking nor agglutination was to be observed. 
Then in each of the tubes was put a quantity of saponin correspond- 
ing in weight to the lowest quantity of derrid of all the tubes: 
after 3 min. laking manifested itself very clearly. 
3. Blood of a cat was treated as stated above and placed in a 
thermostat at 37°. Then it appeared that neither laking nor agglutination 
could be observed, even after 19 hours. In a subsequent series of 
experiments, after 4 hours, laking manifested itself in 2 out of the 
12 tubes, but these tubes contained the smallest quantity of derrid, 
so that action of aleohol must be looked upon as the cause. 
1) The NaCl was added to the solution immediately before using it because derrid 
is precipitated soon after the addition of NaCl. 
