"It is impossible to trace the origin of the disease to the barks; indeed it had not manifested itself at the place whence they come till after it had broken out here. The nearest point infected was Schowlen (at a distance of 200 wersts), and it appeared simultaneously in three different places at Riga, without touching the interjacent country. The first cases were two stone-masons, working in the Petersburg suburbs, a person in the citadel, and a lady resident in the town. None of these persons had had the slightest communication with the crews of barks, or other strangers, and the quarter inhabited by people of that description was later attacked, though it has ultimately suffered most. "None of the medical men entertain the slightest doubt of the action of atmospheric influence--so many undeniable instances of the spontaneous generation of the disease having occurred. Half the town has been visited by diarrhoea, and the slightest deviation from the regimen now prescribed (consisting principally in abstinence from acids, fruit, beer, &c.) invariably produces an attack of that nature, and, generally, cholera: fright, and intoxication, produce the same effect. "Numerous instances could be produced of persons in perfect health, some of whom had not left their rooms since the breaking out of the disease, having been attacked by cholera, almost instantaneously after having imprudently indulged in sour milk, cucumbers, &c. It is a curious circumstance, bearing on this question, that several individuals coming from Riga have died at Wenden, and other parts of Livonia, without a single inhabitant catching the disease; on the other hand, it spreads in Courland, and on the Prussian frontier, notwithstanding every effort to check its progress. The intemperance of the Russians during the holidays has swelled the number of fresh cases, the progressive diminution of which had previously led us to look forward to a speedy termination of the calamity." This is a pretty fair specimen of the _undeniable_ manner in which cholera is proved to be contagious in Europe, and we shall, for the present, leave Dr. Hawkins in possession of the full enjoyment of such proofs. Some attempt was made at Sunderland, to establish that, in the case which I mentioned in my last as having proved fatal there, the disease had been imported from foreign parts, but due inquiry having been made by the collector of the customs, this proved to be unfounded; the man's name was Robert Henry, a pilot:--he died _on the 14th of August_.[11] [Footnote 11: In a former letter I alluded to cases of cholera which appeared this year at Port Glasgow; I find that the highly interesting details of those cases have been just published:--_they should be read by everybody who takes the smallest interest in the important questions connected with the cholera_. The London publishers are Whittaker and Co.]