398 - 



though uniformly dusted over with a fine, whitish, closely-adhering 

 dust. The same result was obtained as in the first experiments 

 mentioned above, i. e., the " mould " died away on the sprayed 

 leaves, and, in those cases where the sprayed plants stood apart 

 from the unsprayed plants the " mould " did not appear on the 

 fresh growth. During the time of the experiment the " mould " 

 continued to increase on the unsprayed plants, and the fresh leav es 

 of these, as they expanded became infested. 



In many of the above experiments frequent and heavy showers 

 of rain fell on the sprayed leaves, but did not wash off the spray 

 owing to its closely-adhering nature. 



Preparation of the Wash. The lime-sulphur wash used in the 

 above experiments may be made first in a very concentrated form 

 by boiling together the following quantities of lime and sulphur : 



Quicklime (in lumps) ... 50 Ibs. 

 Flowers of sulphur . . . . 100 " 

 Water 50 gallons. 



This formula, as well as the method of making and diluting the 

 wash which is described below, is that recommended in Bulletin 

 No. 92 of the Pennsylvania State College Agricultural Experiment 

 Station. 



Some form of heating apparatus is necessary, such as a copper. 

 Iron or zinc coppers are suitable, but copper ones must not be used. 



Place 10 gallons of water in the copper, and start the fire. Add 

 the 50 Ibs. of quicklime. When the slaking is well started, add 

 the 100 Ibs. of sulphur gradually, and mix until a thin even paste 

 is formed, taking care to break up all the lumps of sulphur as far 

 as possible. If too thick, a little more water can be added. When 

 thoroughly mixed, add water up to the 50 gallon mark (using a 

 measuring stick). Boil for one hour, adding water when necessary 

 to keep it at the same level. 



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

 ing of a solution of sulphides and polysulphides of calcium, together 

 with small amounts of other sulphur compounds. There will also 

 be a small amount of insoluble lime and sulphur. 



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

 not reach the liquid. This concentrated wash can be kept, until 

 wanted for use, stored in completely filled and corked stone jars 

 or in barrels. If in barrels the surface of the fluid must be pro- 

 tected from the air by a layer of oil (mineral). 



