of the men, or to hang them upon lines, that they may be exposed to the heat and smoke. It will also be of great service to make the men expose their frowsy clothes to the sun and wind. If a strong infection is suspected, and it cannot be afforded to destroy the clothes, the best means of eradicating the poison is to hang them for a length of time over pots of burning brimstone in a large cask standing endways, with small apertures to admit air enough for the brimstone to burn. Fire in every shape is to be considered as the principal agent of purification, by its heat and the ventilation it occasions, perhaps, still more than its smoke. It has already been repeatedly inculcated, that the great enemies of infection are ventilation and heat. I have mentioned smoke and the effluvia of balsamic bodies, but these are not to be depended on; and it is the more necessary to mention this, as the attention bestowed on more trifling means may divert the mind from a proper regard to what is more essential. It is mentioned by the benevolent Mr Howard, that it is the custom in some parts abroad to scatter fresh branches of pine or spruce in the hospitals, in order to purify the air; but, trusting to this, they neglect the admission of fresh air, which is the only effectual method of sweetening the air. There is reason to think that the open air very soon dissipates and renders inert all infections of the volatile kind, and of course the warmer the air is the more readily it will have this effect. It is accordingly observed, that infection is much less apt to be generated about the persons of men, and that it adheres to them for a much less space of time in a hot climate than in a cold or temperate one. This is a remark, which, so far as I know, has not been made by any author; and, till observation suggested it to me, I fancied the reverse to be the truth. I have seen so many instances of filth and crowding in ships and hospitals in the West Indies, without contagion being produced, and which in Europe could hardly have failed to produce it, or to render it more malignant, that I am convinced there is something in tropical climates unfavourable to the production and continuance of infectious fevers[55]. The ships which bring this fever from Europe in general get rid of it soon after arriving in a warm climate; and nothing but the highest degree of neglect can continue or revive it.