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promptly, all possible sources of impurity out of the dwellings, and either convey them to some neighbouring stream, or so dispose of them as to place them beyond the chance of influencing the atmospheric condition of the town or its neighbourhood. This would include such a supply of water, as would serve to cleanse the streets as well as the interiors of the houses, wherever this might appear to be necessary; and by permitting the sewers to be filled or flushed with water at longer or shorter intervals of time, would suffice for the removal of any source of impurity that might be collected either at the corners of drains, or in their smaller branches, or when, from an unavoidably deficient degree of fall, it might prove to be impossible to keep them clear otherwise.

The effect of existing animal or insect life on the health has been a more curious subject of inquiry of late years, from the revival of an ancient idea that some of the endemic and epidemic diseases-the epidemic cholera, for instance-may be propagated or spread by means of insects, and even conveyed from and to places far apart from one another. The idea is not wanting in curious interest; and it has been advanced from time to time with plausible confirmatory circumstances, and supported with considerable ingenuity. But it is altogether an unproved and merely speculative question, from which no justifiable deductions can be drawn. The effect of insects in the intertropical countries, both during life by their numbers, their rapacity, or their venomous

character, and after death by their effluvia, appears to be sometimes of importance.

Such are some of the principal circumstances which affect the question of climate, and determine its salubrity or otherwise. The deductions from them in individual instances must be governed and modified by the various circumstances of different localities, as well as by the conditions of the system, as to health or disease, which may be under review. Such a practical acquaintance with the sanatory character of any locality can only be obtained by means of extensive data, the result of observations continued during several successive years, as to its mean temperature,-its daily maximum and minimum temperature, the variation in the temperature of the day and the night,-the quantity of rain which falls during the year, and the times at which it falls,-in addition to all the other physical circumstances that have been noticed above, duly and fully ascertained. Furthermore, such a medical history of a district or country should include sufficiently extensive tabular digests of the prevailing diseases, and their individual fatality; such tables specifying, moreover, the total average mortality in reference to the amount of the population,—the observations being extended over many years. Of such conclusively full and satisfactory accounts, there are as yet few from any parts of the world; and until these are sufficiently general to supply the materials for comparison and inference, the subject of climate must be incomplete in its practical detail.

The ascertained principles show why, from its

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comparatively peninsular character, bounded on one side by the Mediterranean, on the other by the Atlantic, the winter climate of the greater part of Europe should be less severely cold, and the summer heats less excessive, than is found to be the case in such parts of the interiors of the large continents as are in the same latitude. The same great principles would go far to determine, without further local data, that one place would be warmer, or have a more equable temperature, or be subject to a less average fall of rain, or be liable to less heavy periodical rains, or enjoy a drier soil; and many other similar and equally important questions might be answered, by merely surveying the general features and circumstances of a country with the eye of a geologist and a physician,—even including the probable liabilities to endemic disease, and its general character. But the confirmation and extension of such observation, by statistical details of the prevailing diseases, their average mortality, &c., would be nevertheless of no small value and interest. How often are the phthisical invalids sent to districts, where phthisis is even more prevalent than it is in the places they have been sent away from,—with the probable result of accelerating instead of deferring the death,-and the certain result of exposing the poor invalid to much fatigue and inconvenience, without there being any chance of benefit accruing therefrom! How often are families found to spend the autumnal months, by way of obtaining a change of air and of benefiting their healths, in places peculiarly remarkable for the

existence of a defective drainage, or other sources of miasmatous impurity; the denizens being liable, in a corresponding degree, to disorders of the stomach and bowels, which it is so important to avoid as much as possible at that period of the year, and from which persons that are unaccustomed to a locality are so peculiarly liable to suffer! How often are scrofulous cases sent to districts where the disease is particularly rife, and the risk of aggravation to the cases of the sojourners is proportionably great, and the chance of the change of air having any good effect is in the same proportion small! Satisfactory details as to the prevailing diseases, and their relative mortality in the different parts of England, may now be referred to in the valuable Reports of the Registrar-General. Similar accounts, of much importance in authoritative interest, are given in the Reports on the health of the seamen of the British Navy, and of the soldiers employed at the different stations and dependencies of this country, in different latitudes, and on the health of the troops employed in the home-service. And although the deductions from these Reports might seem to be of somewhat less value, inasmuch as they are founded on the condition of men who are leading a life of peculiar occupation, habits, &c., and who are for the most part of a selected physical standard, and in the prime of life, yet the comparison of the results obtained from the military and naval records, with those derived from returns embracing the general population, may be fairly said to increase the value and

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importance of such records individually. But these accounts are too few to furnish data for conclusions respecting the sanatory character of more than a few places or countries in the world.

In most cases, in the instance of the invalided, if a removal from their own district be needful, the question of the kind of air they should endeavour to obtain by the removal may be determined, without much difficulty, by giving due attention to the nature of the disease, the function of the affected organ in relation to those of the general system, the tempera. ment and habit of body of the individual, &c.; and thus, the great consideration as to whether a drier or a moister air, a cooler or warmer air, a more quickly changed or more stagnant air, a thinner or denser air, an inland or a saline atmosphere, may be readily, or without much difficulty, determined; and the difficulty of selection may be by so much narrowed and diminished, in an important degree.

Usually, pastoral districts are, for obvious reasons, and in all cases, to be preferred to arable districts of country, for the temporary or the permanent residence of the invalided.

As to England, if a locality the atmosphere of which is of mild but damp character is sought for, the best situations are to be found in Devonshire, and Torquay especially deserves to be mentioned ; the mildest peninsular climate seems to be that of Penzance; the best maritime climates are found in the Isle of Wight, Jersey, Guernsey, and the Isle of Man, -respectively deserving a preference, in proportion