Memoirs of the Caledonian Horticultural Society. 591 



Onions. — In late situations, onions cannot be sown in 

 spring, and transplanted, because the bulbs must be perfectly 

 ripe in the autumn, in order to keep through the winter. 

 They must, therefore, be sown in the preceding autumn, in 

 Mr. Macdonald's manner. Mr. Macdonald generally raises 

 a few potfuls of seedling onions in a stove or forcing-house, 

 so as to have them sufficiently early for planting out. 



Canker. — " Various are the causes said to bring on this 

 desolating disease. Bad or wet soil and subsoil ; exposure to 

 cold bleak winds, in high situations particularly ; stricture of 

 the bark ; frost in spring, checking the circulation of the sap ; 

 external injuries of different kinds ; insects lodging in the 

 cracks, and under the old bark; the infirmities of decrepid 

 old age in those varieties long cultivated in Britain ; improper 

 stocks, or improper grafting. Though others seem to be of 

 a different opinion, yet Mr. Knight thinks that no topical 

 application will do any good, and that the disease is not of 

 the bark but of the wood : and I am inclined to believe that 

 this may frequently be the case ; for, on removing cankered 

 branches, I have often remarked that the very heart was in- 

 fected and discoloured, and the wood under all the three dif- 

 ferent barks rotten or diseased. And that it often proceeds 

 from the infirmities of decrepid old age, in those varieties long 

 cultivated in this island, I am also convinced of, from its being 

 so very destructive to young trees in new gardens, in many of 

 which it is very prevalent, where these old kinds are found." 



50. On the Formation of a Gardener s Library. By Mr. James 

 Smith, Hopetoun House Garden, March 18. 1826. Read April 6. 

 1826. 



It appears to Mr. Smith, that the Caledonian Horticultural 

 Society would advance the interests of gardening by purchas- 

 ing a selection of the best botanical engravings, and laying 

 them on their table for the inspection of practical gardeners ; 

 the same as to engravings of fruits. The principal check to 

 the extended culture of rare and beautiful trees and shrubs 

 is, the ignorance of country gardeners, who have not known 

 them when they were young, respecting their natures. Hence 

 it is, that a suburban garden, of a few square poles, often con- 

 tains more rare and beautiful American trees than a noble- 

 man's park and pleasure-grounds of 1000 acres in Yorkshire 

 or Perthshire. [A good Arboretum Britannicum would go far 

 to remedy this evil.] 



51. On the Cultivation of Peaches and Nectarines on Flued Walls } 

 on screening the Blossoms of Wall Trees by means of Nets and 

 Ferns; on saving Peas and Beans Jrom the Attach of Mice ; 



