THE work described in this paper is the combined effort of a Committee set up to formulate specifications for lime sulphur and colloidal and dispersible sulphur used as fungicides. The Committee was composed of representatives from Long Ashton and East Malling Research Stations, representatives of industrial firms, the Government Laboratory and the Association of British Insecticide Manufacturers.
Sulphur has been used as a fungicide for many years, records dating back over IOO years being available of its use for the control of powdery mildew on vines. Possibly the results in those days were not as good as they might have been, or the quantity of sulphur used to gain control was excessive, but the inevitable investigation showed that better results could be obtained. With increased knowledge of the action of sulphur new products were introduced, and it is now necessary to consider specifications and methods of analysis of some of these newer products.
The Committee mentioned above, in dealing with the group of products containing sulphur as the active principle, agreed that it was desirable to limit consideration to the straight sulphur products-sulphur dusts, flowers of sulphur, green sulphur fumigation products, wettable sulphur, dispersible and colloidal sulphur.
These products could be divided into three groups:
A. Products to be used as dusts,
C.