The solubility of some likely spray substances in solvents containing soap. The preparation of spraying emulsions

Abstract

A lighting (paraffin) oil bought casually, such as is often used in paraffin emulsions for spraying, has been subjected to fractional distillation, and shown to be unsuitable as a spraying oil.Approximate solubilities at room temperature of various “oils” in solvents such as soap solutions with and without the addition of phenols, hydrogenated phenols and pyridine, have been determined. Spray fluids containing paraffin oil, benzene, and aniline in solution are economically possible, but coal tar fractions such as anthracene and creosote oils, will, owing to lack of solubility, have to be applied to plants as emulsions. Cresylic acid is the best aid to solution of paraffin oil, but is probably more injurious to foliage than the dearer, hydrogenated phenol, hexalin.Experiments have been made on the influence of temperature when using soap (sodium oleate) and gelatine as emulsifiers; rise in temperature is found to facilitate the formation of emulsions in soap solutions, but to have a much more complex effect when gelatine is the emulsifier. A possible explanation of these facts is given.