Antivenomous serum, in a dose of 0·01 or 0·05 c.c., neutralizes the bacteriolytic action of 1 milligramme of Cobra-venom, while normal serum heated, even in larger doses, is without effect. The lysin and the antivenomous serum appear also to enter into stable combination; by heating to 80° C., after dilution of the mixture neutral antivenomous serum + venom, the property of dissolving is not restored to the latter.
Pursuing his researches upon the bacteriolytic actions, Noc has also shown that the fresh serums of the rabbit, horse, guinea-pig, rat, and man are capable of destroying them completely. We must conclude from this that venom has the property of fixing the alexin of these fresh serums, and in fact it is easy to show that this fixation takes place by experimenting with hæmolytic alexin, which is much more easy to study; it is sufficient to eliminate the intervention of the hæmolysin proper to Cobra-venom.
With this object, Noc employed horse-corpuscles (which are readily dissolved by fresh rat-serum), and neutralised the hæmolysin proper to the venom by antivenomous serum, which has no effect upon fresh horse-corpuscles and upon the alexin of rat-serum.
For experimental purposes six tubes are prepared with contents as follows:—
(1) 0·5 c.c. of fresh rat-serum.
(2) 0·5 c.c. of fresh rat-serum + 0·5 milligramme of Cobra-venom (0·5 c.c. of a solution of 1 in 1,000).
(3) 0·5 c.c. of fresh rat-serum + 1 milligramme of venom (after fifteen minutes’ contact of the venom with the alexin in tubes 2 and 3 the venom is neutralised by 1 c.c. of antivenomous serum in the case of tube 2, and by 2 c.c. in that of tube 3).
(4) 1 milligramme of venom.
(5) 1 c.c. of antivenomous serum.
(6) 0·5 c.c. of fresh rat-serum + 1 c.c. of antivenomous serum.