that epidemics owe their spread from person to person. To suppose that a disease which is propagated by contagion can rapidly decline and even suddenly cease, just when most persons are affected and the mortality is greatest—that is, when the contagious matter is proved to be in its most active and malignant state—is utterly absurd.

"That epidemics attack the same person more than once, and that relapses are frequent amongst those suffering from them, whereas contagious diseases seldom affect the same individual a second time, and relapses are most uncommon.'

From all this it will be clear that the object of these articles was to prove that all epidemics have their origin in the bad sanitary conditions (as we now say) of the places in which they arise.

It happened then, as very frequently happens in all sciences when the time is ripe for a discovery, that those working in different fields of observation noticed, at the same period, the same facts-some, as for example Dr Maclean, in their posts of observation during the epidemics in distant countries; Dr Southwood Smith in the fever

haunts of London. But it remained for him, collecting together all the experience and generalising from it, to announce the law on which they depend.

Those who thus arrived at the great principle of the connection between defective sanitary conditions and disease, laid the foundation of Sanitary Reform. That connection is an old truth now, one of those about which it is difficult to realise that it could ever have been unknown to the world; but in those days it was unknown and unrecognised, and amongst the few who began to recognise it, there were scarcely any who saw to what wide practical results such truths ought to lead.

My grandfather, however, saw that if the principle were once established, not only would the quarantine laws, at that time absurd and inefficacious, be modified; not only would our merchant ships be released from spending long weary months in unhealthy ports, while their crews were perhaps contracting, from their confinement, the very diseases which they were supposed to have brought with them from foreign lands; not only would the poor sufferers from

plague and yellow fever cease to be imprisoned in the poisoned districts whose air had just given them the pestilence;-not only would these false precautions cease, but the true ones would be taken the causes of disease would be removed; and thus, wherever a knowledge of this law spread and was acted on, disease and death would diminish.

Might not, he thought, something practical be done now and here if these facts were once generally known? Epidemics throughout follow the same laws. Were not the very causes which produce plague in Egypt operating now to produce typhus fever in Bethnal Green and Whitechapel? We might not be able to stop the pestilential, moisture- laden wind that came down to Cairo each year at the time of the inundation of the Nile, but could we not do something towards purifying that which crept into the rooms of our own poor from undrained courts and stagnant pools? Could we not, if people once believed and acted on their belief, banish the yearly epidemic fever from the back - streets of our large towns?

Dr Southwood Smith believed that this great

result would follow from the general acceptance of the truth of the principle he had announced. He gave his life to spreading the knowledge of it.

By the articles in the Westminster Review' something was done towards enlightening the public mind, for I find that they attracted the attention of leading men in and out of Parliament, and were often referred to in the debates in both Houses.

Five years more of daily experience and constant thought passed before his Treatise on Fever' was published.1 It entered fully into all the phenomena of the disease and into the question of its treatment. It added largely to the knowledge of fever existing at that time, and was welcomed by the medical profession. The Medico-Chirurgical Review,' the highest authority of that day, pronounced it to be "the best work on Fever that ever flowed from the pen of physician in any age or country." It was for a long time the standard work on the subject with which it dealt. The most important part of the work, however, as might be expected, is that which relates, not to the treatment of disease 1 Longmans, 1830.

(which has since his time much changed) but to its causes. And here we find an elaboration of the principles laid down five years before in his articles in the 'Westminster Review.' Those articles had been the result of a rapid glance which had gone to the very root of things, though when they were written their writer had held his position at the Fever Hospital for one year only, and had therefore not acquired the large experience of fever which he subsequently attained. But the five years that had passed since they were written could not changecould only strengthen his conviction of the truth of the principles which he had previously expounded.

In the Treatise on Fever,' as in the articles just quoted, it is enforced upon us, that since epidemics are everywhere the same, when they reach our own country we must expect to find conditions similar to those which produce pestilence in foreign countries. He writes as follows:

"The room of a fever patient, in a small and heated apartment of London, with no perflation of fresh air, is perfectly analogous to a stagnant pool