Memoirs of the Caledonian Horticultural Society. 309 



Notwithstanding these observations of Mr. Blaikie, the 

 rapid growth of the Acacia when young, or when cut down 

 to the ground, renders it a very profitable tree as underwood', 

 for the purposes of hop-poles, fencing, or firewood. 



The white oak is recommended by Mr. Cobbett as very 

 tough and flexible, being employed in America for whip- 

 handles. Mr. Blaikie mentions that the whip-handles of the 

 coachmen about Paris are made of the Celtis australis, and 

 are also very tough. They are known by the name of Per- 

 pignans, being procured from that quarter. The Platanus 

 Mr. Blaikie mentions as growing to an amazing size when 

 planted in a moist soil. Several at Troyes, in Champagne, have 

 clean straight trunks of ] 00 ft., and magnificent heads. The 

 timber of the Platanus was proved, by the unfortunate M. de 

 Malesherbes, about forty years ago, to be upwards of twice as 

 durable as that of the elm. 



12. On scraping off the old Bark of Fruit Trees, and on the Dif- 

 ference between the Effect of early and late Pruning. By Mr. 

 Thomas Thomson. 



Mr. Thomson thinks that trees do not decay so much from 

 want of fibrous roots to imbibe nourishment, as from the 

 compression of the alburnum by the indurated outer bark^ 

 hence the advantage of scraping it off in old trees, while 

 removing it from young trees does harm. Mr. Thomson 

 has practised scraping off the outer bark of old trees for up- 

 wards of twenty years. The best season is the spring and 

 autumn ; and, after the operation, the trunk and branches are 

 painted over with a paint made of dried clay, pounded into a 

 fine powder, and mixed with water. ; 



The following observations show the importance of attend- 

 ing to the period of pruning trees, accordingly as it may be 

 desirable to make them push early and vigorously, or to retard 

 and weaken their shoots, or retard their blossoms, so as to 

 protect them from spring frosts: — " Having employed a hedger 

 to cut over a strong, healthy thorn hedge, that enclosed a 

 plantation of considerable extent, he had cut over a large por- 

 tion of it early in autumn, but, being called off to some other 

 duties, the remainder was cut over in the winter and spring 

 following. The whole was cut at 2-3? ft. from the ground, and 

 all done by the same persons. 1 happened to go, in the latter 

 end of the summer, to view the plantation, having thinned it 

 out the preceding autumn, when I was much struck with the 

 unequal growth of the hedge. At first I imputed it to some- 

 thing in the soil, but, on examining, it more minutely, I foimd 



x 3 



