Sulphur
An element constantly present in protoplasm, though only in a very small amount. It is believed to be essential to living beings, and is supposed to be taken by plants from the soil, in Sulphate of Calcium, absorbed in solution by the roots. The sulphate is probably broken up on contact with the oxalates that are formed during growth, and the Sulphur is built up into organic compounds of the protoplasm group. The use of Sulphur to plants is, however, uncertain.
Sulphur as a Remedy. Sulphur is a very useful remedy against the attacks of the Mildew Fungi (see Mildew and Oidium) that live on the surface of the green parts of plants. It is used in the form of "Flowers of Sulphur," dusted upon both surfaces of the leaves, and of young shoots, by means of a Sulphurator (which see). The operation should be performed while the plants are still wet with dew. In this way, Sulphur is applied to Roses, Hops, Vines, &c., usually twice or thrice in a season; but it must be done at such periods as will permit of the Sulphur being all washed off any part that is afterwards to be made use of in food (e.g., Grapes or Hop catkins), before they are gathered. The Sulphur destroys the mycelium of such external Fungi. Weak solutions of Potassium Sulphide have been found to act equally as well as the powder, and are now coming into general use. Dusting with Flowers of Sulphur is a remedy also sometimes employed against larvae of Sawflies, and of Moths; and both the powder and solutions of Potassium Sulphide are used to destroy Green Fly and Red Spider. For the latter, the modes of treatment recommended are to syringe the plants, and then to scrub as vigorously as may be permitted, or to dip the shoots into the solution, which is prepared by carefully mixing 40z. of Sulphide of Calcium with 2oz. of soft soap, and then adding hot water up to one gallon in all. This solution should be made use of twice or thrice, and will be found a most useful application; or fluids containing Sulphur, e.g., Gishurst Compound and Veitch's Chelsea Blight Composition, may be employed with success.