The injection of the serum and the dressing of the wound should be performed as in the case of poisonous bites in human beings. _Influence of the Doses of Antivenomous Serum injected, and of the Time that has elapsed since the Venomous Bite._--I have stated above that antivenomous serum possesses a preventive and curative power of such intensity, that it is capable in a few minutes of rendering animals into which it has been injected absolutely insensible to the most strongly neurotoxic venoms, such as those of _Naja_ or _Bungarus_. On the other hand, I have established the fact that, the more sensitive are the animals to intoxication by venom, the greater is the quantity of antivenomous serum necessary to immunise them passively or to cure them. In experimenting upon mice, guinea-pigs, and rabbits, it is found that in order to preserve, let us say, a mouse of 25 grammes against inoculation with half a milligramme of venom, which is ten times the lethal dose for this little animal, it is necessary to give a preventive injection of 1 c.c. of serum; while half a cubic centimetre of the same serum is sufficient to render the dose of half a milligramme of venom innocuous, when venom and serum are mixed _in vitro_ before being injected. In the case of the guinea-pig, it is likewise found that the dose of serum to be injected preventively, in order to protect the animal from intoxication by ten times the lethal dose of venom, is about _twice as much_ as the quantity of the same serum that it is sufficient to mix _in vitro_ with venom, in order to render ten times the lethal dose of venom innocuous. If we inject into animals first venom, in doses calculated to kill the controls of the same weight in from two to three hours, and the serum _fifteen minutes afterwards_, it is found that the quantity of serum that must be injected in order to prevent death is about _thrice as great_, as that which neutralises _in vitro_ the dose of venom inoculated. It is also found that _the amount of curative serum that an animal intoxicated by venom must receive is inversely proportional to its weight_. The experiments upon dogs, performed at the Pasteur Institute at Lille by my collaborator C. Guérin, are highly demonstrative in this respect.[107] A dog of 12 kilogrammes, inoculated with 9 milligrammes of venom (a dose lethal to controls of the same weight in from five to seven hours), is completely cured on receiving, _two hours after inoculation with the poison_, 10 c.c. of serum. When the treatment does not take place until _three hours after the injection of the venom_, it is necessary to inject 20 cc. of serum in order to prevent the animal from dying. With a longer delay than this, death is inevitable, since the bulbar centres are already affected, and paralysis of the respiratory muscles commences to appear. These facts show that:--