Materials and Formulas. 175 



purpose is practically confined to greenhouses and conserva- 

 tories, and even there only few insects are affected by it. It is 

 most rapidly applied by evaporating in a sand bath over an oil 

 stove, but extreme care must be given that it does not take fire, 

 as then it will instantly destroy all the plants. Red spider and 

 related insects are said to be destroyed by the fumes, and treat- 

 ment should be made as soon as they are discovered, or even 

 before. Sulphur may also be evaporated successfully by plac- 

 ing it upon the heating pipes. It is well to mix it with an 

 equal amount of lime, and then add water to form a thick 

 paint, with which the pipes may be covered. When applied in 

 a dry form directly to the plants, it possesses little value as an 

 insecticide. A moist atmosphere in the house probably renders 

 the fumes more effective. 



Sulphur is one of the most valuable fungicides for the treat- 

 ment of surface mildews, and it has long been used for this 

 purpose. Previous to 1880, it was almost the only fungicide 

 used in Europe, and it did excellent service in controlling the 

 European mildews which attacked the vine and many other 

 plants, whether grown under glass or in the open. Out of 

 doors it was commonly applied in a dry condition, being blown 

 upon the plants by means of hand bellows. Under glass it was 

 used in three ways : in the form of powder, when mixed with 

 water, and when evaporated from the heating surfaces. The 

 first method was executed in the same manner as out-doors. 

 When mixed with water both the sulphur and the water assist 

 in destroying many pests, and it is a common practice to make 

 such applications. The proportions of the two vary greatly. 

 It has been recommended to use 1 ounce of sulphur to 5 gallons 

 of water, and also as much as 1 pound to 1 gallon. The more 

 dilute mixtures are more easily applied, and if the work is 

 thoroughly done, are, on the whole, equally valuable. The fumes 

 of sulphur for treating mildews are obtained as described above. 

 When the powder is used out of doors the value of the remedy 

 undoubtedly rests in the fact that the sulphur gradually gives 

 off fumes on account of the heat of the sun, and the mildews 

 yield for the same reason that they do when the powder is evap- 

 orated under glass. 



One of the most valuable preparations of sulphur is known as 

 Grison's liquid, which see. 



