REMARKS ON CULTURE OF ROSES IN I'OTF. 1 S3 



of roses, that is to say, the production of them out of their natural 

 season; hut it is nevertheless necessary to provide them some pro- 

 tection, and at least " a local habitation," if they are to he bloomed 

 in that perfection which throughout this paper I have been antici- 

 pating. The most suitable structure then which could be devised 

 would be a small pit, facing the south-east, just large enough to admit 

 of a path at the back in the inside, and heated by means of a branch 

 from some contiguous hot-water apparatus ; the plants would occupy a 

 platform between this pathway and the front of the pit ; and thus, 

 whilst every convenience would be afforded for paying them the 

 attention they might require, they would also enjoy a full share of 

 that most indispensable requisite to healthful vegetation, that real 

 essential, light. During their winter (that is when they are at rest), 

 they would require only to be kept safe from injury by frost, and con- 

 sequently would not need the application of artificial heat ; but when 

 the period of their development arrives, an increase of temperature 

 becomes necessary ; this, however, as in all similar cases, should be 

 progressive, so that the health and constitutional strength of the 

 plants may not be weakened by sudden and unnecessary excitement ; 

 a degree of temperature, ranging at first at about 40° and rising gra- 

 dually to 55° by day, when the blooms are about to expand, would be 

 such as I should adopt ; but above every other consideration as regards 

 the temperature, I would require that the heat during the night should 

 be not less than 5° below the average of that of the day. 



Plants can only exercise their functions of respiration, digestion, 

 and assimilation, under the influence of light ; at least it is only by the 

 assistance of this agent that they can go on satisfactorily ; now the 

 application of heat has the effect of compelling plants to exercise 

 these vital functions, and therefore to force them into a state of action 

 without the aid of the most essential requisite, by maintaining a high 

 temperature whilst they are enveloped in darkness, is to violate all 

 that w r e know of the very nature and principles of their existence ; and 

 I am sure I cannot use stronger language than this to convince every 

 one (if at least my argument is a correct one) that it is a most inju- 

 dicious and injurious course to pursue ; and what in this sense applies 

 to the use of heat, applies equally to that of moisture. 



With regard, then, to moisture — for to this we next direct our atten- 

 tion — much depends on the season, the state of the weather, and the tern- 



