1910.] Lime-sulphur Wash for Use on Foliage. 187 



The wash thus prepared will be an orange-red liquid, con- 

 sisting of a solution of sulphides and polysulphides of 

 calcium, together with small amounts of other sulphur com- 

 pounds. There will also be a small amount of insoluble lime 

 and sulphur. 



Strain through butter-muslin, and store at once where air 

 cannot reach the liquid. This concentrated wash can be kept, 

 until wanted for use, stored in completely rilled and corked 

 stone jars or in barrels. If in barrels, the surface of the 

 fluid must be protected from the air by a layer of oil (mineral). 



Before use as a spray on the foliage of plants the concen- 

 trated wash obtained as above requires to be diluted. The 

 amount of dilution which is necessary in order to avoid 

 "scorching," varies with the character of the foliage or plant 

 to be sprayed, and can only be ascertained by experiment. 

 In the experiments described above, a lime-sulphur wash 

 having a specific gravity of 1*01 was used; this is obtained 

 by adding from about 20 to 23 gallons of water to every 

 gallon of the concentrated wash — according to the specific 

 gravity of the latter, which will vary slightly. When diluted, 

 the wash must be used at once. Hydrometers with a speci- 

 ally prepared scale and directions for use can be obtained, 

 price 3s. 6d. each; by means of one of these instruments the 

 specific gravity of the concentrated or diluted wash can 

 instantly be ascertained. Under the conditions in the experi- 

 ments described above a lime-sulphur wash of the specific 

 gravity roi produced no "scorching" on the leaves of the 

 hop, gooseberry, or apple. On the young, tender foliage 

 of roses in the greenhouse, "scorching" resulted with a wash 

 of this strength ; in such cases the wash should be used at half 

 strength. It is possible that under certain weather conditions 

 this weaker strength will be necessary for the hop, goose- 

 berry, and apple also in order to avoid "scorching" the 

 foliage. In all cases the lime-sulphur wash should be first 

 used on an experimental scale, the specific gravity of the 

 diluted wash (or the number of gallons of water added to 

 each gallon of the concentrated wash) being carefully noted. 

 A few plants should be sprayed with a wash having the 

 specific gravity roi, and then, if necessary, further dilution 

 with water should be made. 



In the boiling together of the lime and sulphur a chemical 



