_Mr. B._--That is strange;--and, so gratuitous does the assertion appear to me, that I should be better satisfied were you to support it by some examples. _Dr. A._--Well then, I may instance for your satisfaction, the well known influence of peculiar winds combined with moisture, and which, although they may produce little or no variation in the thermometer will rapidly rob the body of its heat; the north-west winds which so commonly blow in the southern provinces of France are decidedly more mischievous to the pulmonary invalid than the March winds that desolate the more delicate frames in our own country, and yet the thermometer in this case affords no indication of their nature. _Mr. B._--No one who wishes to form a just estimate of a climate, can doubt the propriety of taking the prevalence of wind, and the degree of atmospheric moisture into the account; although reasoning, from analogy, I should not suppose that this latter circumstance would be prejudicial; look at the moist and foggy atmosphere of Holland, and yet I am told that catarrhal affections are extremely rare in that country. _Dr. A._--Moisture must make both heat and cold more sensible; the one, by diminishing perspiration, the other, by increasing the conducting power of the air;[137] humidity therefore may be an injurious, or a salutary condition, according to circumstances; but you are greatly mistaken in supposing that the Dutch owe their immunity from Catarrh to the dampness of their climate, for it is to be imputed to the greater equability of its temperature. _Mr. B._ You no doubt place great stress upon the advantage of an equable climate. _Dr. A._ I consider equability as the most important condition of all; especially where the temperature ranges at about 60° of Fahrenheit. It not only diminishes the chance of aggravating pulmonary disease by preventing Catarrhs, but it serves to preserve a genial and regular action of the skin, to keep the balance of blood constantly on the surface, and to prevent any undue congestion of it in the lungs. Besides, it is acknowledged on all sides, that consumption is most prevalent in countries and districts which are subject to great and rapid changes of temperature, and that it is comparatively rare in those which are free from the diurnal changes and sudden transitions which so characterise that of our own island. _Mr. B._ Nothing can be more convincing than such reasoning;--but tell me for what reason you consider the temperature of 60° as an essential condition under these circumstances. _Dr. A._ It is evident that no climate, however equable it may be _thermometrically_, can be considered as such in a _medical_ point of view, if its temperature ranges much below the degree I have mentioned; because in that case a material change must always occur whenever the invalid quits his apartment, and goes into the open air. So that I consider a cold climate must _in effect_ be always regarded as a variable one.