To the question, which has so often been triumphantly asked, of its progress to the Russian frontiers being conducted by caravans along the great highways of human intercourse, and what else than contagion could cause it to be so carried? An admirable journalist has already replied by asking in his turn, on what other line than amongst the haunts of men could we possibly have found, or detected a human disease? And surely the question is most pertinent, for in those barbarous regions that interpose between Russia and India, where the wolf and the robber hold divided alternate sway, and isolated man dares not fix his habitation, but must congregate for safety; where else than in those great thoroughfares could the disease have found its food; or if beyond these, man, almost as ignorant and as savage as the wolf, could have been found; who under such circumstances would have recognised, described, and testified to its existence? Even at Sunderland, amongst ourselves, its existence was long hotly disputed by the learned of the faculty; and the fatalist barbarian of these regions would have dismissed the enquiry with a prayer of resignation, while he bowed his head to the grave, or if his strength permitted, with a stroke of his dagger against the impious enquirer who had dared to interfere with the immutable decrees of fate. The stories too of its importation into Russia, are exactly the same as have come to us from our own Gibraltar, in the case of the yellow fever, and may be expected to come from every other quarter where a well paid officious quarantine is established to find infection in its own defence, and to trace its course in proof of their own services and utility. Under such circumstances, this well gotten up drama of importation may be rehearsed in every epidemic, adapted in all its parts to every place and every disease, they wish to make contagious. First will be presented, as at Gibraltar, the actual importers--their course traced--the disease identified--its reception denounced, and quarantine established; and this will go down until sober minded disinterested men become engaged in the enquiry, when it will turn out in all probability, that the importers, as at Sunderland, never had the disease--that it was in the place long before their arrival--that in its supposed course, it either had no existence, or had long ceased--in fact that the importation was a fable, the product either of design or an alarmed imagination. On this point I shall not here farther dwell, but proceed to the still keenly disputed question of its contagious, or non-contagious nature.