SULPHUR FOR MILDEWS. gi 



perfectly dormant, such treatment is not followed by any 

 evil effects. 



During the past spring several growing plants were 

 exposed to the action of the gas when used according to 

 the above directions. Tomatoes, eggplants, oranges, and 

 roses were used. The day following the treatment showed 

 that all the plants were injured, but to what extent could 

 not be well determined. After two weeks had passed, 

 however, the effect of the treatment was plainly seen. The 

 tomato plant died ; the eggplant and the rose lost all 

 their foliage, but fresh leaves were appearing on the 

 stems ; the orange suffered the least, since only the 

 young leaves were affected. The mites had all been 

 killed, so that in this respect at least the experiment was 

 successful. 



Other trials were made with the gas, using the same 

 kinds of plants, but it was found to be impossible to de- 

 stroy the mites without injuring at least some of the 

 plants. The use of hydrocyanic gas for the destruction of 

 greenhouse pests can therefore scarcely be recommended. 

 It should also be remembered that this gas is exceed- 

 ingly poisonous, and must not be inhaled. 



Sulphur. This element is of the greatest service in 

 greenhouse work. It is an invaluable agent for the de- 

 struction of mildews, and is also of great assistance in 

 overcoming red spider. As commonly used, it is mixed 

 with an equal bulk of air-slaked lime or some similar 

 material, and then water, oil, milk or some other liquid 

 is added until a thick, creamy paste is obtained. This is 

 then painted upon the heating surfaces in the house, and 

 the sulphur fumes are given off. The same result can be 

 obtained much more rapidly and energetically by heating 

 the flowers of sulphur until it melts ; the fumes are then 

 given off in great abundance. Our practice has been to 

 put the sulphur in a shallow pan and then set it over an 

 oil-stove, having the flame turned just high enough to 

 keep the sulphur in a melted condition. Almost contin- 



