This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Of the many methods which have been recommended for destroying worms, corrosive sublimate is the most efficacious. By means of it, may be cleared a piece of grass from which it seemed almost impossible to eradicate the worms, the surface of it being always covered with oasts, and looked most untidy; but for eighteen months after this was applied, scarcely a single oast was to be seen. Use the solution of the corrosive sublimate of the strength of one ounce to forty gallons of water, having dissolved the sublimate first in a little hot water, and thoroughly mixed it. The requisite quantity of each being prepared, the whole should be well stirred together, and cmmenoing at one end of the lawn with the watering-pot, without a rose, let the surface be entirely flooded; if any part of the ground is missed, the grass will soon be as bad as ever with the worm-oasts. Directly after the solution has been applied, the worms will make their appearance, which have always picked up. The dose may be made sufflciently strong to kill them on the surface, or even in the ground; but this is attended with danger to the grass, particularly on light soils. Picking them up is the best. If possible, the ground should be gone over a second time, after an interval of three or four days.
Attention should also be paid to the state of the ground, which should neither be soaked with rain nor parched up with drought, but in a middle state. Great care is at all times necessary in using this deadly poison. It is also useful in destroying slugs, etc.