VENTILATION. 77 



Ventilation is an inexhaustible subject, and one of much 

 moment to the horticulturist. In the orchard-house, how- 

 ever, it is much simplified, though I see that Mr. Rivers 

 recommends fewer top ventilators than were of use at first, 

 and certainly cold currents of air, especially if charged with 

 excessive moisture, cannot be suitable to peach culture. Pre- 

 cautions must therefore be taken to guard against these, as 

 also against strong winds acting directly on the ripened fruit. 

 Ventilation is chiefly necessary to carry off noxious vapors, 

 and it is inconceivable how soon these are generated. A 

 minute quantity of sulphurous acid will cause every leaf in 

 the house to drop in a day. In forcing-houses ventilation 

 in the spring is rather injurious than beneficial. When the 

 air is charged with moisture it is more suitable for plants in 

 a growing state than when they are ready to rest. " The 

 skilful balancing of the temperature and moisture of the air, 

 and a just adaptation of them to the various seasons of growth, 

 constitutes tlie most complicated part of a gardener's art." — 

 Lindley^s Theory of Horticulture. 



Enough, however, has been said on these subjects, and 

 perhaps by this time the reader is reduced to that condition 

 in which Horace, anxious to prepare for his supper party, 

 querulously tells his servant, " Persicos odi, puer, apparatus," 

 which, as the botanical name of the peach is " Persica," 

 may be thus rendered : " Gardener, I am sick of your peach 

 training." 



The principal suggestions are — summer pinching reduced 

 to a method, and perfected in the winter pruning of peaches 

 on the alternate system ; and the placing the trees diagonally 

 at short intervals. I have not dwelt much on the obvious 

 advantage of being able in this way to occupy a valuable wall 

 with a succession of fruits, precious to the cultivator as this 

 must be, because it seemed to me that the being able to 

 shorten the period in which the wall space could be covered 

 with fruitful wood, completely overshadowed other considera- 

 tions, for in horticulture, as in other matters, the gain of a 

 year is of inestimable value. 



