This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
It is well known what an admirable thing coal oil is in destroying insects on plants when not too strong, but it •cannot be diluted with water. In the attempt to mix it, the oil would stay on the top, and the water go to the bottom of course. Mr. Knight, in the London Florist mentions a plan that he has been pursuing with success. He uses coal oil in the proportion of one wine-glassful to four gallons of water. He keeps the two mixed with the syringe in this way: before using he squirts a syringe full into the lower part of the vessel, and immediately draws it in again and applies it to the plant. By following this method, the oil and water becomes well mixed.