None knew whence the Destroyer came, nor in what hidden corner he lurked. The Registrar for the district we are describing closes his return for Walworth, for the week ending Sept. 8, 1849, in the following words: "It (the disease) has spread over the whole district--into almost every street--and taken persons of all classes, from the most respectable to the poorest." Men hunted for it in the unhealthy drain, and endeavoured to destroy the unwholesome vapour; they searched for it in what they drank, and hoped to get rid of it by boiling the water; they impregnated the air with lime, and in every court and alley you passed you inhaled the powerful chloride. Then a change was produced, and the returns of deaths gradually lessened every day; and those who for days and weeks dare not look into a newspaper, for fear of encountering those dark tables of death, were now eager to see the returns, and congratulate their neighbours on the daily decrease. "From the painless nature of the attack," says the same Registrar, "persons seemed to be unconscious how highly necessary it is that immediate attention should be paid to it." Thousands fell through this neglect, who, if the disease had first made its appearance attended by severe pain, would not have lost a single hour without seeking medical aid. Like a flood that slowly undermines a bank, and which the proprietor regards not when he sees so tiny a current dribbling and oozing through, and scarcely bowing the grass between which it trickles, so came the Destroyer--slowly and almost imperceptibly undermining the current of life, and eating out the foundations, until there needed but one mighty rush, and all was over beyond recovery, and the work of destruction was completed. A little precaution would have saved thousands of lives in London alone. Let us then agitate for pure air and pure water, and break through the monopolies of water and sewer companies, as we would break down the door of a house to rescue some fellow-creature from the flames that raged within. It rests with ourselves to get rid of these evils; and scarcely one in a hundred will be foolhardy enough to oppose the sanitary measures which are already in motion. To aid these proposed improvements, we deemed it our duty to add to the "Picturesque Sketches of London" a brief but faithful description of the dreadful disease which caused almost every street in the metropolis to be hung in mourning. [Illustration] CHAPTER XXI. GREENWICH.