59 



years, that this disease becomes progressively more 

 fatal to each variety, as the age of that variety, beyond 

 a certain period, increases ; that if an old worn-out 

 orchard be replanted with fruit trees, the varieties of 

 the apple which I have found in the catalogues of the 

 middle of the seventeeth century, are unproductive of 

 fruit, and in a state of debility and decay. 55 * 



Among the individuals particularly liable to be in- 

 fected, are those which have been marked by an ex- 

 cessively vigorous growth in their early years. We 

 once had one which for the first twelve years of its 

 existence was remarkable for the unnatural large size 

 and abundance of its annual shoots. It then became 

 grievously affected by canker, which at length de- 

 stroyed it. 



Trees injudiciously pruned, or growing upon an 

 uugenial soil, are more frequently attacked than those 

 advancing under contrary circumstances. The oldest 

 trees are always the first attacked of those similarly 

 cultivated. The Golden Pippin, the oldest existing 

 variety of the apple, is more fequently and more seri- 

 ously attacked than any other. 



The soil has a very considerable influence in in- 

 ducing the disease. If the subsoil be a ferruginous 

 gravel, or if it is not well drained, and the soil be 

 aluminous, and effective means are not adopted to 



* Some doubts as to the Efficacy of Mr. Forsyth's Plaster 

 by T. A. Knight, Esq. P.L.H.S., &c, 1802. 



