The King of Prussia makes a similar _amende_, and the Emperor of Russia convinced by the same experience, abolished or greatly relaxed his quarantines several mouths ago. [Footnote 26: Vide Reports from Russia.] I am by no means prepared to assert, because I cannot possibly know to the contrary, although from the analogy of other disease I do not believe it, that the Cholera Morbus may not become contagious under certain conditions of the atmosphere, but these cannot be made subject to quarantine laws, and I am fully prepared to acknowledge, that as in the case of other epidemics, it may be made contagious through defective police; but independent of these, it possesses other powers and qualities of self-diffusion, which we can neither understand nor controul. Such, however, is not the case with that other phantom of our quarantine laws--the yellow fever--which can never, under any circumstances of atmosphere, without the aid of the last be made a contagious disease. I speak thus decisively from my experience of its character, as one of the survivors of the St. Domingo war, where, in a period of little more than four years, nearly 700 British commissioned officers, and 30,000 men were swept away by its virulence; as also from subsequent experience, after an interval of 20 years, when in the course of time and service, I became principal medical officer of the windward and leeward colonies, and in that capacity, surveyed and reported upon the whole of these transatlantic possessions. It was my intention, in these times of panic, to designate to my countrymen, in as far as I could, the true essential intrinsic contagions of the British Isles, (for such there are, and terrible ones too,) which prevail under all circumstances of season, atmosphere, and locality, as contradistinguished from the factitious ones, of our own creating, and the imaginary or false which often spread epidemically, (for there may be an epidemic as well as contagious current of disease)[27] although they possess no contagious property whatever; as well as the foreign contagions, which if we relax in due precaution, may, at any time, be introduced amongst us--but the unreasonable length of this letter, for a newspaper communication, warns me to stop.