Red spider is invisible until it appears as red blotches upon foliage. Water, and still more water, combined with smoking cures it. Shower infested plants heavily every day for a fortnight, smoke with tobacco twice a week, and keep well dusted with either tobacco or pyrethrum powder. Mealy bugs, which are white and woolly, as big as grains of wheat, should have a sulphur dusting after smoking and bathing. All the big scales, which are never very numerous unless plants are fatally neglected, should be hand-picked, then the plant well washed with whale-oil soapsuds dashed with carbolic acid. San José scale, which is almost invisible but feels like fine rough sand upon the under sides of leaves and over stalks, is so deadly and difficult any plant found infested should be burned at once, the pot broken, and the earth soaked with boiling water. Cures for it there are, but too difficult for amateurs, withal somewhat dangerous. Buy tobacco dust, make tobacco water. Pour a gallon of boiling water upon a pound of tobacco stems, let stand a day, keeping warm, strain and use. Cut the spent stems fine and mix through potting soil. Enough tobacco water to color it mixed in makes a plunge bath more effective against insects. Make smudges thus: put a few slivers of wood or half a dozen matches crossed in a small flat tin, cover with either pyrethrum powder, tobacco dust, cut up stalks, unspent, or flowers of sulphur mixed with fine damp sawdust. Light, see that there is not too much blaze, and set beneath plants. Do not make smudges big enough to give out scalding heat; better two or three small ones if heavy smoke is required. Red rust and brown scale, the special enemies of palms, need to be washed off with strong carbolic soapsuds and a soft brush before bathing and smoking. =Earth Worms=: Lime water is the remedy for earth worms. Stick holes in the earth quite to the bottom, then pour on clear lime water (see section Renovators) till it stands on top. The worms will crawl up to escape it. Lime water is also good to sweeten sour earth. Give a half cup after the hot-water treatment. Dig up the earth in pots so as to keep a light, clean surface. Green scum, while not dangerous, does not make for plant health. =For Roaches=, dip cut potatoes in arsenic mixed with sugar and lay cut side down on the pots and about them. Gather up every morning, dropping instantly into a vessel of boiling water—this to destroy such insects as remain alive. But never put out poison if there are children in the house.