Abroad we find that, unhappily, the cholera has made its appearance at Hamburgh; official information to this effect arrived from our Consul at that place, on Tuesday the 11th inst. (October). The absurdity of cordons and quarantines is becoming daily more evident. By accounts from Vienna, dated the 26th September, the Imperial Aulic Council had directed certain lines of cordon to be broken up, seeing, as is stated, that they were inefficacious; and by accounts of the same date, the Emperor had promised his people not to establish cordons between certain states. We find at the close of a pamphlet on cholera, lately published by Mr. Searle, a gentleman who served in India, and who was in Warsaw during the greater part of the epidemic which prevailed there this year, the following statement:--"I have only to add, that after all I have heard, either in India or in Poland, after all I have read, seen, or thought upon the subject, I arrive at this conclusion, that the disease is not contagious." In confirmation of the opinion of Mr. Searle, we have now the evidence of the medical commission sent by the French government to Poland. Dr. Londe, President of that commission, arrived in Paris some days ago. He announced to the minister in whose department the quarantine lies, as well as to M. Hely D'Oissel, President of the Superior Council of Health, that it was proved in Poland, entirely to his satisfaction, as well as to the satisfaction of his five colleagues, that the cholera _is not a contagious disease_. The Minister of War also sent _four_ medical men to Warsaw. Three of them have already declared against contagion; so it may be presumed that the day is not far distant when those true plagues of society, cordons and quarantines against cholera, shall be abolished. Hear the opinion of a medical Journalist in France,--after describing, a few days ago, the quarantine and cordon regulations in force in that country:--"But what effect is to be produced by these extraordinary measures, this immense display of means, and all these obstructions to the intercourse of communities, against a disease not contagious; a disease propagating itself epidemically; and which nothing has hitherto been able to arrest? To increase its ravages a hundred-fold,--to ruin the country, and to make the people revolt against measures which draw down on them misery and death at the same time." What honest man would not _now_ wish that in this country the cholera question were placed _in Chancery_; where, I have no doubt, it would be quickly disposed of. I shall merely add, that the ten medical men sent from France to Poland, for the purpose of studying the nature of cholera, have all remained unattacked by the disease. October 15, 1831. LETTER V.