296 transactions of the Horticultural Society. 



tain friend near Haddington, to let us know the heaviest crop 

 of potatoes he has ever heard of having been grown in 

 Scotland ; and Mr. Fraser would much oblige us by similar 

 information with regard to Ireland. 



48. On the Cultivation of the Pine- Apple. By Thomas Andrew 

 Knight, Esq. F.R.S.&c. President. Read August 19. 1828. 



That no part of this paper may be lost on our readers, we 

 shall give it entire, which we are not sorry to do, confessing 

 ourselves unable, either satisfactorily to abridge it, or to draw 

 any conclusions from it that would not, we fear, be attributed 

 to our prejudices. (See Encijc. ofGaid., p. 538 — 540., and the 

 first article of Retrospective Criticism, in the present Number.) 



" I have now completed a long course of experiments upon the culture 

 of the pine-apple in the dry stove, the object of which has been to ascertain 

 the means by which that species of fruit might be most advantageously^ 

 grown, and particularly at those periods of the year, when the scarcity ot 

 other fruits gives it an additional value. In these experiments 1 have 

 endeavoured to ascertain the effects of excess of drought, and of moisture ; 

 and of very high, and of very low, temperature. I have, of course, sacri- 

 ficed many plants in experiments, which I neither found, nor expected to 

 find, successful ; but from these I have derived information, which, I 

 believe, will prove useful to the cultivators, and advantageous to the con- 

 sumers, of that species of fruit.* 



" The effects of a very dry atmosphere necessarily were an inspissated 

 state of the sap of the plant, and this, as it does in all other similar cases, 

 led to the formation of blossom buds and of fruit^; and it thus operated 

 upon some pine-apple plants to such an extent as to cause even the scions 

 from their roots to rise from the soil with an embryo pine-apple upon the 

 head of each, and every plant to show fruit, in a very short time, whatever 

 were its state and age. 



" Very low temperature, under the influence of much light, by retarding 

 and diminishing the expenditure of sap in the growth of the plants, compa- 

 ratively with its creation, produced nearly similar effects, and caused an 

 injuriously early appearance of fruit. 



" Very high temperature, if accompanied with a sufficiently humid state 

 of the atmosphere, I found beneficial at all seasons of the year under a 

 curvilinear iron-roofed house, for this admitted as much light even in the 

 middle of winter, as the pine-apple plants appeared to require. 



" Many months previous to the publication of Mr. Daniel's very excel- 

 lent communication in the Transactions of this Society [Gard. Mag., vol. i. 



" * I have, in a communication last year to the Horticultural Society 

 {Gard- Mag., vol. iv. p. 365.], shown that the mould in pots circumstanced 

 as those which contain my pine-apple plants are, acquires a temperature 

 very nearly equal to that of the aggregate temperature of the air in the 

 house, but not subject to such extensive variations. Thus, if the highest 

 temperature of the air within the house during the day be 90', and the 

 lowest during the night be 70°, the temperature of the mould in the pots 

 will nearly approximate the arithmetical mean 80°: and surely the intelli- 

 gent gardeners of the present day must be fully sensible that mould at 

 eighty degrees is warm enough without the aid of the irregular and ungo- 

 vernable heat of a baik bed, whatever their ignorant predecessors, who first 

 introduced the bark bed into the pine stove, may have thought. 



