14 



the market in sticks, called "sulphur rolls," and in the shape of needle- 

 shaped crystals and rhombic prisms, but these forms are not of use in 

 dealing with insects and fungous diseases. The powder is very valuable 

 for combatting surface fungi (external) and was long used for that pur- 

 pose in Europe, but of late years the copper compounds have been more 

 commonly used. When burned, its fumes form a very active disinfect- 

 ant, but, since moisture must be present in the atmosphere before it 

 will act (at which time it will also bleach colored fabrics, wall paper, 

 etc.), its use in this way has been largely replaced by formaldehyde, 

 mercuric chloride, and other substances. 



Lime Sulphur Washes. 



These washes have come into use during the last few years in com- 

 batting the San Jose Scale. They have also been found to be very 

 effective in destroying other kinds of the smaller insects, and are con- 

 sidered by many to be one of the best general "cleaning up" sprays that 

 have been devised. In addition to their insecticidal value, they are 

 efficient fungicides. 



A number of formulae have been recommended for the preparation 

 of these washes. Those usually adopted in Ontario, as given by Prof. 

 Lochhead,* are as follows : 



Boiled Wash : 



Fresh lime .' 20 pounds. 



Sulphur (flowers) 15 



Water 40 gallons. 



"With warm water make the sulphur into a paste, put in the lime 

 and add about 15 gallons of warm water with stirring. The sulphur paste 

 may be added after the lime has been slaked. Boil for an hour and a half 

 in a kettle, or, better, in a barrel with live steam. Make up to 40 gallons 

 with hot water; strain into spray tank and apply while warm." 



Some of our fruit growers were at first inclined to use even larger 

 quantities of lime ; but this past season many of them increased the 

 amount of sulphur, using the following formula : 



Fresh lime 20 pounds. 



Sulphur (flowers) 18 



Water '. 4° gallons. 



The length of time recommended for cooking the wash varies from 

 one-half hour to two hours. Possibly the best plan is to boil until the 

 color of the whole mass is tinged with green. This is undoubtedly the 

 best way to prepare the wash, for the boiling insures the combination 

 of the sulphur and lime. Very little is prepared by boiling in a kettle, the 

 live steam method is much more convenient and cheaper. Where small 

 quantities are wanted, one of the following methods, in which the heat 



* Thirtv-Pixth Annual Report of the Entomological Society of Ontario. 



