This is particularly well illustrated in the history of various races typically dissimilar.* But aside from this, and even in the same race, diverse forms of deterioration are seen to follow distant removals from the sphere of ancestral nativity and residence. The first wave of Anglo-Saxon emigration always exhibits some depreciation in physical stamina by transportation to this continent; its progeny is less positively developed, has less physical stamina, and seems to be under the constant ban of climatic antagonism, since, whenever returned to its original home, it re-assumes the national tendencies of its parents.

The deteriorating influences of climate are best seen upon masses of men, as in the case of European troops transported to the tropics; or, after several generations, among those in civil life. While on the other hand, the therapeutic virtues of climate, being generally observed only in individual cases, and remembered as a striking example of benefit, are not predicable in favor of whole races. I doubt, in fact, whether the history of the world exhibits a single instance of a race of men being improved by transportation to a foreign clime. On the other hand

* From a large number of autopsies of negro soldiers made during our late Civil War, it was definitively proved that the anatomical development of organs originally intended to subserve the wants of a tropical climate, has not in the least been changed by long residence in a different region; and that consequently, the large mortality of the unmixed negro race in temperate and northern zones is the simple result of a change of habitat without corresponding change in the organs of vegetative life. Thus the brain, lungs, and spleen, were invariably found to be smaller than in the white race, while the liver particularly, and intestinal canal generally, were found to be much larger.

numerous instances prove the contrary. The northern nations which invaded the Roman Empire; the Asiatic Turks who invaded Europe; the Spaniards in South America; or the English, French, and Irish in North America; and the negro race in Canada, all show positive signs of having encountered a climatic influence tending to their deterioration. The Esquimaux race transplanted to our latitude, would soon succumb to the cumulative influences of climate despite any form of dietary they might adopt, precisely as Dr. Kane's men all tended to develop scrofula in the Arctic regions, in the face of the best sanitary precautions they could employ. And if this deterioration was so soon manifested in them, how would it have been with future offspring, had they brought American wives and colonized there? Would the children have inherited more vitality than their parents possessed? Or would they ultimately become transformed into Esquimaux? Since neither of these things could happen, it is fair to infer that such a colony would not survive a third generation. Therefore is it that the recognised benefit of climate to certain individuals, like that derived from special articles of food, proves only its adaptation to personal conditions existing in them, and not to the race in general to which they belong.

If such be the influences of climate, that it not only develops tendencies, but increases them when already existing, it follows that its correlations to temperament must be of the closest and most significant character. That it may originally have been the father of temperament in a less locomotive age of

the world, is beyond question. That it is so now cannot be equally admitted. How far, therefore, many systems, in which lurking tendencies to disease may be manifesting themselves, and where no exaggerations of temperament will alone explain them-how far such systems may be suffering from the want of harmony between their organs and the qualities of the surrounding atmosphere, should always constitute an element of inquiry with the philosophical practitioner. In therapeutics we speak in general terms of the beneficial effects of change of air, pointing to such diseases as asthma, whooping-cough, catarrh, phthisis, etc., etc., in proof thereof. But we have hosts of sickly children, with weak, flabby membranes, tending to excessive generation of mucus, and atonic glands but half performing their elaborating function; we have weak, nervous women, of characteristic pallor, mere stalks of human celery, in whom furs and furnaces can scarcely maintain the rhythm of a languid circulation; we have legions of invalids whose sources of disease, often obscure and undiscovered, are all referable to a common debility in the function of innervation, who would often be better remedied by change of air, than by those most convenient charmers, Alteratives. Variety in food is not a simple act of condescension to the palate, but a recognition of those organic necessities which require to be separately gratified. And, inasmuch as, within the circle of this law, certain temperaments require a larger proportion of particular aliments, some demanding excess of animal over vegetable food, and vice versa, in order to continue in positive health, so

the experience of all ages shows that certain conditions of atmosphere are, like food, either acceptable and thus benign to one class of beings, or a source of irritation, and thus injurious to another. While change and variety in diet are constantly insisted upon as essential pre-requisites to health, change of air is only thought of in the presence of actual disease, and the great fact is lost sight of that the atmosphere may have been the first, last, and most constant cause in the production of the disease itself, to which state it has slowly dragged the system down, by a series of functional derangements expressing only excess in physiological activity. No better illustration of this law exists, than that afforded by the chronic pallor and tendency to struma in childhood, which afflicts the permanent residents of great cities, particularly where manufacturing arts taint the general atmosphere; or, better still, the characteristic complexion of the inhabitants of malarious regions, whose whole economy reveals the presence of an atmospheric poison constantly disturbing the balance between the nervous and circulating systems. To such persons medicine is practically only palliative, since the active cause continues always in advance of medication, and no system of prophylaxis, however rigidly pursued, will insure perpetual immunity against so subtle an agent as the atmosphere.

It becomes important, therefore, as an element of prophylaxis, that the quality of the atmosphere should be related to the wants of the system as manifested by its temperament, and temperament is in turn greatly modified by age. Thus, childhood requires a

dry, pure, bracing air to stimulate the glandular system, and repress the tendency to extreme sensibility of the mucous membranes and cerebro-spinal system, while old age requires the opposite. In this respect, women closely resemble children, and the same rules apply to them. In middle life, and when temperamental physiognomy is more clearly indicated, the wants of each system can readily be inferred from the character of its functions, and the predispositions to disease which they exhibit. The seasons, by their change, give us a change in the temperature and relative moisture of the air; but they do not affect, in a similar way, the pressure of the atmosphere in a given locality. This remains a more constant quantity in the problem of physical life, and one whose influence has until recently been greatly overlooked. All are equally influenced by it, even though not equally sensible of it. The first step in relieving the system from this incubus consists in occasionally exchanging climates, by passing from a moist to a dry atmosphere, from a marine to a mountain climate, or contrariwise. And the sojourn there should be sufficiently prolonged to make a very definite impression upon all the organic functions. Merely flitting in a railway carriage through a country does not bring us under the specific influences of its climate, unless it be a particularly sinister one. In order to be benefited radically by a change of air, we must tarry long enough in it to effect a change in the molecular constitution of organs. * Nothing short of this will

* Taking the combined weight of all the excreta as a gross expression of the daily waste of the body, and dividing the entire weight of the