Hundreds of people, we will say, for instance, come daily from a sickly district to a healthy one, and yet no disease for some time appears; but at last an "inexplicable condition of the air," and "not appreciable by any of our senses" (admitted by Dr. Macmichael and others as liable to occur, but _only in aid_ of contagion), take place; cases begin to appear about a particular day, and nothing is now more easy than to make out details of arrivals, there being a wide field for selection; and even how individuals had spoken to persons subsequently attacked--had stopped at their doors--had passed their houses, &c.[8] Causation is at once connected with antecedence, at least for a time, by the people at large, who see their government putting on cordons and quarantines, and the most vague public rumour becomes an assumed fact. We even find, as may be seen in the quotation given from Dr. Walker's report, that contagionists are driven to the "somehow or other" mode of the introduction of cholera by individuals; so that it may be deplored, with respect to this disease, in the words of Bacon, that "men of learning are too frequently led, from ignorance or credulity, to avail themselves of mere rumours or whispers of experience as confirmation, and sometimes as the very ground-work, of their philosophy, ascribing to them the same authority as if they rested upon legitimate testimony. Like to a government which should regulate its measures, not by official information of its accredited ambassadors, but by the gossipings of newsmongers in the streets. Such, in truth, is the manner in which the interests of philosophy, as far as experience is concerned, have hitherto been administered. Nothing is to be found which has been duly investigated,--nothing which has been verified by a careful examination of proof." [Footnote 8: Since the above was written it has been very clearly shewn how easily proofs of _this kind_ may be furnished to all disposed to receive them. We perceive that a disease officially announced as _the true_ cholera, has existed for nearly a month past at Sunderland, and that among the thousands of people who left it within that time, nothing could be more easy, had the disease appeared epidemically in other parts of England, than to point out the _particular individual_ who had "brought it" in some way or other; and this is the manner in which all the fables about the propagation of cholera from one district to another have gained credence. (Nov. 24th.)]