on the Pine- Apple. 187 



name, I feel in justice bound to acknowledge his undivided claim 

 to the credit of its discovery. 



Much of the success of this remedy depends upon the manner 

 of applying it : I will, therefore, describe minutely the process 

 practised by myself. In the first week of November, the plants 

 were taken out of the bark bed, a few of the lower leaves pulled 

 off, and every insect that could be discovered, by the most 

 careful inspection, was rubbed off. The plants were then well 

 syringed with clear water, for the purpose of washing away any 

 insects that might have fallen into the axils of the leaves. A 

 strong lather of soft soap was next dashed over them from a 

 syringe, observing that not the smallest portion of the leaves 

 remained untouched ; and, while wet, they were dusted all over 

 with a powder composed of black sulphur, yellow sulphur, and 

 soot, mixed in such proportion as to resemble the colour of the 

 leaves as nearly as it was possible to make it. After top-dressing, 

 the pots were replunged, and the plants treated in the usual way. 

 Early in February, it became necessary to increase the tempera- 

 ture of the house to 70° (in consequence of vines trained to the 

 rafters being at that time in blossom), and the plants were then 

 frequently syringed; the powder, which had adhered closely to 

 the leaves, was in this way gradually washed off; and, by the 

 end of summer, the plants had nearly regained their natural 

 colour. They, also, were entirely free from insects ; and have 

 continued so ever since. 



It should be observed, however, that the complete destruction 

 of these parasites is not always to be obtained by a single dress- 

 ing ; for, owing to the great difficulty of discovering every insect, 

 when plants are badly infested, it is highly probable that a few 

 may be overlooked : and, in that case, the plants upon which 

 they are found should immediately be subjected to a repetition 

 of the whole process. It must not be supposed that the washing 

 and powdering will kill the insects that remain undisturbed upon 

 the plants : and yet this quality is attributed to most of the nos- 

 trums which I have read. Respecting the assistance afforded by 

 the sulphur and soot towards effecting this desirable end, it 

 might be remarked that, in Mr. Wilson's opinion, either of the 

 ingredients alone, or, indeed, almost any other powder, would be 

 equally efficient; the rationale of its action being to prevent the 

 adhesion to the leaves of any young insects which might possibly 

 be bred on parts of the plants from whence it is impracticable 

 to dislodge the old stock, as, for example, among the bases of 

 the leaves. I not only concur with Mr. Wilson, but am farther 

 inclined to believe that the oily coating, left upon the cuticle by 

 the soft soap, will answer the desired purpose fully as well, with- 

 out any powder whatever ; but, as this opinion is founded upon 

 a single experiment, it needs confirmation. 



