_Mr. B._--I am well aware of the difficulties to which you refer; circumstances of a moral nature, with which the physician can rarely become sufficiently acquainted, must necessarily have considerable weight in directing the decision; but in my own case it is fortunate that no such embarrassment can impede your judgment. My only object and care is the restoration of health, and my means are sufficient to enable me to pursue it in any way which may give the fairest promise of success. _Dr. A._--You mistake me, it was not to embarrassments of that kind that I was alluding. _Mr. B._--Can then any other source of difficulty exist? To a medical practitioner who is in the habit of sending his patients to all parts of Europe in search of health, the real and comparative advantages of each locality must surely be well known. _Dr. A._--Far otherwise, my dear friend; there are few subjects upon which medical men have more widely differed. It is true that we send our pulmonary sufferers to various parts of the continent, and that we receive from them a multiplicity of reports; but then they are often totally at variance with each other upon those very points which are generally considered as the least questionable; and when we attempt to reconcile this discordance, by an appeal to meteorological records, and registers of prevalent diseases, we are mortified to find that the evidence necessary for forming a safe and practical conclusion, requires a union of industry and accuracy which has not hitherto been found to exist in a sufficient number of collateral observers. Nor must it be forgotten, that the disease, for the cure of which the invalid is persuaded to emigrate, may require a very different atmosphere in its different stages and forms; and after all, how often does it happen that the sufferer is not sent abroad, until every chance of palliation has gone by. _Mr. B._--I do not hesitate to declare that such conduct, on the part of a medical adviser, is as cruel as it is unprincipled; my confidence however in your integrity satisfies me that you will never abandon an unhappy sufferer to such a useless alternative; I must therefore request you to state your opinion, _generally_, as to the peculiar conditions upon which you consider the eligibility of a climate, in the cure or palliation of pulmonary affections, to depend. _Dr. A._--This I shall do most cheerfully, especially in conversation with one, whose philosophical pursuits will have already instructed him in those principles, from which our conclusions are necessarily deduced.--Congenial warmth, and, above all, equability of temperature, are the first objects of inquiry in the theoretical comparison of climates; but these cannot be _practically_ ascertained, in relation to their effects upon the human body, by the thermometer; because they are constantly liable to be modified by causes of which we have no other indication but that afforded by our sensations.