dry bundles are packed together, in another wet bundles are packed together, in other places they are about evenly intermixed. There is a third

point to be noted about this imaginary heap. In some places the bundles are packed very close; in other parts they lie wide apart, with ample clear space between them.

We must further imagine that on to this stack of fuel there are continually falling, at irregular intervals, but constantly falling and certain to fall, lighted brands or torches. In such a condition of things it is clear that fires are inevitable. All that is doubtful is the extent to which they will occur. This will depend on a number of factors; for instance, on the number and fierceness of the burning brands; whether they fall in places where the fuel is thick, or where it is scanty; and whether they fall on wet or on dry material. Much also will depend on whether the brands are noticed at once and picked out, or whether they are overlooked till a patch is well alight. But it is clear that, sooner or later, there is every probability, if not the certainty, of a very fierce blaze.

The foregoing comparison, with one important reservation, fairly represents the state of things in

our own and other countries during inter-epidemic

periods. At such times we are free from the disease. But cases of smallpox are often imported from abroad where it is endemic; they come to this country from Europe, Egypt, Africa, India, and many other parts, even from China. They arrive, for instance, at Hull, Bristol, Liverpool, London. Port Sanitary Authorities are constantly stopping them; but they cannot keep them all out; for cases may come in at ports where there is no regular medical inspection.

There is also a class of case which is alluded to in the reservation just mentioned. Infection may be imported in a latent form. No mere medical inspection can keep out a patient who is in the incubation period of his disease. He is then, to all intents and purposes, perfectly well. He settles himself comfortably at home, and then breaks out with smallpox. It is the persons who arrive during their twelve days of incubation and settle down unobserved, who are apt to do the most mischief. Infection may also be imported in clothes, or in rags and other raw material for manufacture. In these ways smallpox can always succeed in obtaining an entrance.

The following is a striking example of how on one occasion smallpox was introduced into this country. It was related on July 13th, 1900, to members of the Epidemiological Society by Mr. T. W. Russell, M.P., then Parliamentary Secretary of the Local Government Board. He said: "I had a most extraordinary case before me yesterday, in which I am sure every one here will be interested. A deputation came to see me from Lancashire, representing several large towns, in connection with the spread of smallpox of a special character. There had been something like 100 cases in these Lancashire towns within the last few months; and the story as detailed to me yesterday, I confess, interested me, and will probably interest the members of this Society. It appears that a man left Moscow, in Russia, intending to travel to Staleybridge, in Lancashire. He was ill when he left; he arrived at Flushing; and when the vessel was boarded by the medical officer, the captain reported that there was no sickness. The man came on to Queenborough, landed there, and it was noticed that he had to be carried through the baggage-room on a chair; but he accounted for that by declaring that he

was suffering from rheumatism, and could not walk. He was put into the train, and travelled to Manchester, and from Manchester to Staleybridge, where he died the day after his arrival from virulent smallpox. The interesting point is, that almost every one who travelled with him in the compartment from Queenborough to Manchester took smallpox; the ticket collector at Manchester took smallpox; those who travelled with him from Manchester to Staleybridge in another train took smallpox; and something like 100 people, I think, had smallpox spread by means of this simple case. The real question is: could that have been prevented? Well, that is exactly the crux of the situation."

So much for a general consideration of the manner in which smallpox may be introduced. Next comes the question of the general policy of meeting it. That need not detain us long, for the decision does not rest with us. Pursuing the same line of thought as before, it may be said that there are three possible policies for protecting a wooden village from fire. The first is to secure that all the houses are built of wood which is non-inflammable. The second is to allow perfect liberty of

building material, and to maintain a fire-prevention organisation warranted to limit and extinguish any outbreak that may occur. The third is a combination and modification of the first two. In regard to smallpox, Germany furnishes an example of the first policy; our own country of the third. Parliament sanctioned the relaxation of routine vaccination in 1898, and loosened it still more in 1907. At the present time very large numbers of the population are susceptible to smallpox, and these numbers are increasing. As the susceptible material increases, so does the risk, and so does the responsibility of those who are engaged in keeping smallpox out.

Some outbreaks seem to have required a combination of circumstances to bring them about. For instance, the 1871 and 1902 epidemics in this country were preceded by an unusual prevalence of smallpox among our neighbours in France; it is obvious that must increase the chances of its being brought to us. If smallpox in that country is not now as prevalent as it was in the years named, we have to remember on the other hand that the facilities of modern travel have brought various countries, where smallpox is endemic,