Hydrophobia Antidote. - Although this is not an antitoxin nor a serum it is conveniently considered here. A rabbit is inoculated from the spinal cord of an animal dead of hydrophobia, other rabbits are inoculated from this, and so through a series until the spinal cord (which is the chief seat of the virus in hydrophobia) contains a virus the incubation period of which is seven days. The spinal cord loses its virulence when exposed to the air, so that a series of spinal cords (each of which originally contained a virus the incubation period of which was seven days) can be prepared of greater or less virulence according to the time during which they have been exposed to the air.

Uses of Hydrophobia Antidote.

It is found that if a patient who has been bitten by a rabid dog is inoculated first with a rabbit's spinal cord of a low degree of virulence, and the next day with one of higher degree, and so on increasing the virulence of the injection, hydrophobia does not usually develop in him if the treatment is begun soon after the bite. The reports of the use of this suggest that some of the deaths after treatment may be due to it rather than to the bite. Inasmuch as the incubation period of hydrophobia is so extremely variable, the pathological findings so inconstant and the symptoms so diverse, there is some reason for doubting the existence of the disease in man. At least the majority of alleged cases have been shown to have been those of various diseases. For this reason the antidote possesses but little interest save to those who are interested in spreading hydrophobia-phobia.