OF THE PINE-APPLE. 



347 



dark day, when the hot-house is not very warm, a 

 person will make a great progress therein in the 

 course of a few hours. 



The following mixture I have found to be 

 equally efficacious with the former ; and although 

 it is not so proper to be applied to exotic plants, 

 on account of its disagreeable smell, it seems very 

 likely to be of great use to fruit-trees against walls, 

 as well as to melons in frames, which also are often 

 much injured by the Acarus. 



Take two ounces of soft green soap ; 



One ounce of common turpentine ; 



One ounce of flowers of sulphur. 



Put these ingredients into a proper vessel, and 

 pour upon them one gallon of boiling water. Let 

 the whole be well worked together with a whisk, 

 which will bring it to a strong lather, and cause 

 the ingredients to incorporate. 



The mixture must be used milk- warm, and kept 

 gently stirring, during the time of using, to pre- 

 vent the sulphur from subsiding. 



As the Acari generally reside on the under-side 

 of the leaves of plants, from the position of wall- 

 trees, it is impossible for any external application 

 to destroy the insects that are so situated : how- 

 ever, it is very probable that the strong smell of 

 the turpentine and sulphur may be so disagreeable 

 as to cause them to change their residence, and to 

 seek for refuge «on other plants. 



I must beg leave to observe, that I think this 

 mixture may be of considerable use in preventing 



