influence of this special substance which has been generated in the gall, the bacteria remain rooted to the spot where they are first situate, and only a passing and exceedingly slight local affection results, which on its departure leaves the animal with an immunity from rinderpest lasting some four months. A number of interesting investigations have not unnaturally been stimulated by this remarkable discovery, and researches on the properties inherent in the gall of healthy animals of various kinds have been recently carried out by Dr. Neufeld, of the Institute for Infectious Diseases in Berlin, which are, however, of a too technical nature to deal with here.

As an illustration of the practical use to which Koch's gall immunisation method may be put in dealing with outbreaks of rinderpest, reference to a recent report furnished by the Health Officer of Shanghai may be of interest. Dr. Arthur Stanley describes the outbreak as follows:

"A large herd of cattle infected with cattle-plague was brought to Shanghai from the Tanyang district, around the Grand Canal, for export to the allied troops in the north of China. The disease spread to an adjacent dairy, most of the cattle dying. On this dairy becoming infected a police cordon was established round it to prevent ingress and egress of cattle and ingress of persons unconnected with the dairy, while

the outside infected herd was removed to an isolated part of the settlement. Having been previously convinced of the futility of police cordons in the prevention of cattle-plague, I was not surprised to find, within a short time, that the disease had spread, by the meeting together of cattle-coolies at a common tea-house, to three other dairies at a distance of a quarter, a half, and two miles from the original source of infection.

"As the animals are not, as a rule, taken away from the immediate vicinity of the dairy, there being no grazing fields, and as neither fodder nor dung is taken from one dairy to another, it is practically certain the infection was carried by the dairy-coolies.

"Immediately on this second series of dairies becoming infected it was resolved to apply the gall immunisation method of Koch as being the means at hand. About 1,500 cubic centimetres were collected from the gallbladder of a rinderpest animal, and 10 cubic centimetres were injected into the dewlap of each of the twenty remaining cattle in the dairy.

"The injection caused slight local swelling and tenderness, but no constitutional symptoms and no alteration in the milk-supply, an important matter in a dairy. In all sixty-eight cattle were injected with cattle-plague gall. Of these, seventeen were among isolated uninfected herds; the remaining fifty-one belonged to infected herds, and among the latter eleven died of cattle-plague subsequent to the injection."

Dr. Stanley points out that ten of these animals, judging by the time which elapsed after the injection, when they showed the first symptoms of

the disease, must have been already infected when the injections were made; the eleventh animal, however, undoubtedly contracted the disease after and in spite of the injection.

"Considering," continues Dr. Stanley, "the usual excessive mortality during an outbreak of this disease, the result may almost be compared to the success of vaccination against small-pox. Three young bullocks, each having received 20 cubic centimetres of cattleplague gall, were purposely exposed to severe infection. They remained well, while unprotected animals around them died of the disease."

In the domain of immunity there is, however, no more fascinating or interesting story than that which deals with the discovery and elaboration of a cure for snake-bites, a discovery which, while attracting but comparatively little attention in this country, should prove of paramount importance to our fellow-subjects in the great Indian Empire. The significance to India of Professor Calmette's discovery of a specific cure for snake-poison may be gathered, indeed, from the statistics which have been compiled of the number of deaths attributed by Indian officials to this cause alone, amounting, it is said, to some 22,000 annually.

The Pasteur Institute in Paris has despatched many pioneers of science to various quarters of the globe, but perhaps no scientific missionary has

produced more fruitful results than has Dr. Calmette. It was while acting in the double official capacity of Médecin de 1st Classe du Corps de Santé des Colonies and Director of the Bacteriological Institute of Saïgon, in Cochin China, in the autumn of 1891, that Calmette first commenced his experiments on the neutralisation of serpent venom in the animal system.

He had, indeed, exceptional opportunities in the matter of serpent venom wherewith to carry out his investigations, for during the rainy season a village in the neighbourhood of Bac-Lieu (Cochin China) had been attacked by a band of most venomous serpents.

These creatures, driven by the floods into the very huts of the natives for shelter, created a terrible panic, and no fewer than forty individuals were bitten by them. The panic was certainly not without justification, for these serpents belonged to the species known as naja tripudians, or cobra de capello, renowned for the deadly nature of their venom, and widely distributed over India, Burmah, Sumatra, Java, Malacca, and Cochin China; but until Calmette set to work to systematically study the nature of this reptile's venom but little precise or reliable information had been obtained as to its character.

The governor of the district gave orders that as

many as possible of the reptiles were to be captured alive and forwarded to the Director of the Bacteriological Institute, and a plucky Annanite actually succeeded in securing ninety specimens, which were forwarded in a barrel to Dr. Calmette.

This formidable gift was received with enthusiasm by the director, who realised the importance and scope of the inquiry, which he at once set himself to systematically work out.

Forty of these reptiles arrived alive, and several were at once sacrificed to secure their venom glands. Each gland, resembling both in size and shape a shelled almond, contains about thirty drops of venom, and in this transparent limpid liquid is embodied a toxin of extraordinary strength. It was, of course, necessary in the first instance to ascertain, within as narrow a limit as possible, the exact degree of toxic power inherent in the venom, and to determine, if possible, the precise lethal dose in respect of each variety of animal experimented upon.

A correct calculation of the quantity of venom required in every case was, however, found to be quite impossible, for so virulent is the poison that a single drop of an emulsion produced by pounding up eight glands in 300 grammes of distilled water is sufficient, when introduced into the vein of a rabbit's ear, to kill it in five minutes. All the

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