24< Transactions of the Botanical and Horticultural Society 



intended to be the permanent trees, and by that means crops 

 of them would be obtained before those that are later in 

 coming into bearing produced any. The earlier bearers 

 could, of course, be cut out as they interfered with the others." 

 For this very judicious paper, the Society awarded to Mr. 

 Falla their gold medal. 



2. On the Diseases to tvhich Onions, Cauliflowers, Broccolis, 3fc., are 

 subject. By Mr. Thomas Smith, C.M.H.S., Gardener to Matthew 

 Bell, Esq., Woolsington. 



The same paper was published in the Transactions of the 

 Horticultural Society of London^ and its essence will be fouqc} 

 in our First Volume, (p. 293.) 



3. On the Method of warming Horticidtural Stoves. By the Rev. 



R.H. Vv^iliiamson, Newcastle. 



The most valuable and original paper in this collection. 

 The writer argues that, however reasonable it may seem to 

 dispense with the bark-bed or other bottom heat, seeing there 

 is no such thing as a natural hot-bed, yet that the conclusion 

 drawn is wrong, because " plants in a hot-house are in a 

 situation altogether different from what they would be out of 

 doors in their native climates, particularly with regard to the 

 state of the atmosphere in which they grow." 



The following quotation includes the greater part of the 

 paper ; it is long, but we fear that to abridge it would lessen 

 its value to young gardeners unaccustomed to a very condensed 

 form of reasoning : — 



" Air is an elastic fluid, which expands by heat ; therefore, 

 all particles of it, as they become warm, unless they meet 

 with some external impediment, will ascend till they reach a 

 stratum of similar density to themselves : the heat will con- 

 sequently always be greatest at the radiating or reflecting sur- 

 face. Hence, the earth at any given place, unless cooled by 

 evaporation or some accidental cause, will be warmer than the 

 air immediately above it; and this, again, will be warmer than 

 portions of the atmosphere more remote. This is very sen- 

 sibly felt in places at any considerable variation of altitude. 

 Now, although for all horticultural pui-poses, owing to the 

 comparatively small height of any vegetable production, the 

 temperature at the same time and place may be considered as 

 uniform, still the lower parts of the plants are, if any thing, 

 rather in the warmer medium. Moreover, in tropical climates, 

 the earth, from the great power of the sun's rays, and their 

 continued action, becomes heated to a considerable depth. 

 Now, in all horticultural stoves, the heat will be found to vary 



