( 692 ) 
4. Experiment on blood of a guinea-pig, as stated above; after 
18 hours nothing could be observed; after 20 hours there was laking 
in all tubes, including the tube with the “normal fluid”. 
5. Cow’s blood was treated in the same way; after 20 hours 
neither laking nor agglutination could be found. 
6. The same. negative result can be mentioned of human blood: 
no laking or agglutination after 19 hours. 
From all this it appears that derrid has neither a laking nor an 
agglutinating effect on the blood of the above-mentioned animals, and 
that in the cases where laking had manifested itself, this must be 
put down to action of alcohol or the long duration of the experiment. 
Effect on respiration. 
This effect was studied from the surviving eel’s head which, according 
to KourraBKko’s method *), was prepared and nailed on to a board. In 
the hepathic vein was tied a cannula, through which Ringer-Locke’s 
solution, with or without derrid, could be led from 2 Mariotte 
bottles. The ‘‘derrid solution” was a dilution of 1: 1.000.000; to 
the “normal solution” was added a quantity of alcohol and NaCl 
equal to that already being in the ‘‘derrid solution”. The respiration 
and the movements of the heart were registered on the kymograph. 
On addition of derrid convulsions of the muscles of the whole head 
manifested themselves in fits and, independent of these, also intensified 
movements of the gills; after continued action these movements 
stopped, as well as the convulsions. So here we have a poison 
first stimulating and then paralysing the central nervous system, 
and especially the respiratory-centre. 
When frogs were subcutaneously injected with derrid (0,5—6 mg.), 
respiration stopped, besides other symptoms that shall be mentioned 
below. Action of aleohol was excluded. 
The same symptoms were observed with white mice that were 
subeutaneously injected with derrid (0,1—3 mg.). 
Rabbits, injected with derrid in a vein of the ear (1.6 mg. per KG.), 
soon died through stopping of the breath; however, if immediately 
after this stopping of the breath tracheotomia and artificial respira- 
tion were performed, the animals lived, because after some time 
spontaneous respiration showed itself again; then the trachea and the 
wound were sewn up. This effect was further studied in the following 
manner: Rabbits were narcotised with urethane; then tracheotomia 
1) Kouuranko. Arch. Internat. de Physiol. Vol. IV 1906 —1907 p. 437. 
