worst disease, to which those of the best fruits 

 are subject in the best soils and upon the best 

 walls. It is what has not been (that I know of) 

 taken notice of with us, till I was forced to ob- 

 serve it by the experience of my gardens, though 

 I have since met with it in books, both ancient 

 and modern. I found my vines, peaches, apri- 

 cots, and plums upon my best south walls, and 

 sometimes upon my west, apt for several years 

 to a soot or smuttiness upon their leaves first, 

 and then upon their fruits, which were good for 

 nothing the years they were so affected. My 

 orange-trees were likewise subject to it, and 

 never prospered while they were so ; and I have 

 known some collections quite destroyed by it. 

 But I cannot say that ever I found either my 

 figs or pears infected with it, nor any trees upon 

 my east walls, though I do not well conjecture 

 at the reason. The rest were so spoiled with it, 

 that I complained to several of the oldest and 

 best gardeners of England, who knew nothing 

 of it, but that they often fell into the same 

 misfortune, and esteemed it some blight of 

 spring. I observed after some years that the 

 diseased trees had very frequent, upon their 

 stocks and branches, a small insect of a dark- 

 brown color, figured like a shield, and about 

 the size of a large wheat-corn ; they stuck close 

 to the bark, and in many cases covered it. 



