268 



JOURNAL OF HOBTIOULTDKE AND COTTAGE GARDENER. 



[ October 8, 1888. 



the second crop of tubers from which the skins slip when 

 handled, will not keep and answer the purpose of seed, and it 

 is conRigned to the pigs accordingly. Nothing can be more 

 fallacious than this notion. I have proved year by year for 

 ten years consecutively, that Potatoes taken up in an unripe 

 state to the extent of their skins slipping off with the slightest 

 touch will, if carefully managed, produce crops in all respects 

 fully equal— indeed, 1 am quite safe in going a step further and 

 saying slightly superior, to the crops produced by seed which 

 had been left in the ground to fully ripen before being taken 

 up. On this point I am glad to see the experience of " Upwards 

 AND Onwaeds " so entirely in consonance with my own. — J. W. 



CAUSE OF FLAVOUK IN FRUIT. 



A VERY short article in your number of September 2Uh, on 

 the cause of colour and flavour in fruit, is so interesting that 

 I wish to be allowed to make a few remarks on the subject, 

 especially as it is in reference to a letter of mine upon '• the 

 orchard-house railway " iu the previous week's number. 



Your correspondent " G. S." attributes the superior flavour 

 of fruit having the advantage of being placed quite in the open 

 air, under favourable circumstances, to the non-permeability of 

 glass to certain rays of the sun. It has been demonstrated 

 that the sun emits three distinct rays — the actinic (or chemical, 

 as " G. S." clearly explains them), the luminous, and the 

 calorific or heating rays. All these are employed during the 

 whole growth of a plant in bringing it to perfection ; though it 

 is generally supposed that the actinic ray is most active in spring 

 and upon the early-developed plant, the luminous in summer, 

 during its period of growth, and the heating ray in the autumn, 

 at the ripening period. Thus Nature econoniises her forces, 

 and brings them to bear at the period they are most needed to 

 perfect the works of her hand. It would be very interesting if 

 " G. S." would give us further information on this subject ; 

 for the time has come when we cannot long hope to carry out 

 our schemes (in fruit-growing more than in other matters) by 

 guesswork, but that they must be able to stand the test of 

 science, and a clear reason be given for the jjros and the coiitras 

 of our operations. 



I have no doubt whatever but that the intervention of glass 

 does affect the actinic rays. Dr. Brewster, in the " Philoso- 

 phical Transactions," so long ago as 1810 (page 106), goes so 

 far as to say that bodies will not radiate their heat through 

 glass, and ascribes all the effects which are supposed to have 

 been thus obtained to a secondary radiation from the glass, 

 which becomes heated by the reception of the rays issuing from 

 the primary source ; at all events, it is not improbable that 

 glass checks radiation as much as an opaque substance of equal 

 thickness with the glass. This brings me to the question I 

 wish more particularly to lay before your readers. Hitherto I 

 have done little more than reiterate what has been stated bv 

 "G. S." 



The question of radiation at night and its influence on the 

 growth and development of fruit, is not sufliciently recognised. 

 The gardener goes to bed at night under the full impression 

 (and he is right to a certain extent), that his plants are at rest 

 also, or ought to be, and so dismisses them from his mind until 

 the morning. But nothing is ever perfectly still in nature ; a 

 constant reaction is going on between day and night. In 

 the day the luminous rays of the sun aid the leaves to decom- 

 pose the carbonic acid gas in the air, which is absorbed by the 

 trees, and takes the place of the oxygen gas they evolve ; at 

 night oxygen is absorbed, and carbonic acid to a certain extent 

 given out. The radiation which takes place where trees have 

 the full benefit of the open air at night, but not otherwise, 

 greatly facilitates these natural operations, and tends to keep 

 the trees in a healthy state. In the animal economy, which is 

 only a higher development of the vegetable, we fully recognise 

 the necessity of rest undisturbed, and of offering no check to 

 the excretions, forming as they do as important an element of 

 health as the secretions. We cannot, therefore, interfere with 

 this radiation without materially affecting the natural functions 

 of the tree. Experience, independently of science, tells us what 

 a Bubtilo agent it is in the growth of plants. A narrow coping, 

 for instance, on the top of a wall is sometimes quite sufficient 

 protection to save the early blossoms on our trees by arresting 

 the radiation. Is it not fair to infer that the same coping will 

 influence the lipeningof the fruit in summer from the same 

 cause ? How much more the covering of a whole roof ? 



it may be said^tbat the latter remarks involve a contradic- 



tion in stating the valuable services rendered to the trees by 

 night air and radiation, and in the next sentence recognising 

 the necessity of interfering with them ; but we must not lose 

 sight of the fact that our subject has reference to Peach trees, 

 &c., which are in an abnormal state in our climate. The 

 object, therefore, should be to meet this difficulty by protection 

 in spring and increased heat in summer when required, and at 

 the same time to interfere as little as possible with the natural 

 functions of the tree. As may be supposed, we find by experi- 

 ence that the more carefully this is attended to the finer will 

 be the fruit in size and flavour, and the more luxuriant the 

 foliage of the trees. Now, I venture to say that the " orchard- 

 house railway," as an assistant to the orchard house itself, is 

 by far the best means to this end that has yet been brought 

 forward. The labour it involves is so slight that every change of 

 atmosphere, whether for retarding or advancing the growth of 

 the fruit, may be taken advantage of all through the year 

 without the sUghtest inconvenience ; and under the guidance 

 of a clever gardener such results may be produced as will fully 

 satisfy him. The advantage of removing lights overhead have 

 long been recognised by our best gardeners ; but the advantages 

 it offers are very inferior to the railway system, for these reasons 

 — it interferes with the Grapes, which can now be grown in the 

 orchard house without injury to the trees, but which require 

 less ventilation and more heat than fruit trees ; a roof fitted 

 with moveable sashes would cost more money than the railway ; 

 the trouble of moving them would be infinitely greater ; and 

 when done the effect upon the trees would by no means be 

 equal to the advantages of the free circulation of the air all 

 round. 



I have already trespassed too much upon your space, but 

 hope to be allowed on a future occasion to give the result of 

 some experiments I am making upon radiation, as immediately 

 connected with the roots of fruit trees.— J. F., Southacre Rec- 

 tory, Brandon. 



THE IMPROVERS OF THE HOLLYHOCK. 



MccH has been written in your pages in reference to the 

 improvement of the Hollyhock. England seems to take all 

 the credit to herself, forgetting to introduce her canny neigh- 

 bour, the Scot. 



Better Hollyhocks were to be found in Scotland before either 

 Mr. Chater or Mr. Paul were known as growers of that flower. 



I hope some of our old Scotch growers, such as Mr. FouliB, 

 of Fordel, Mr. Porr, and Mr. Foulis, of Woodhouselee, who 

 exhibited and competed for prizes more than thirty years ago, 

 will favour the readers of your paper with the history of their 

 earliest productions. — D. G. M. 



DARKENING THE COLOURS OF FLOWERS. 



E. King, SjyitalficWs, wishes for information upon " darken- 

 ing flowers, the most suitable soil for Dahlias, also the best 

 seed of Dahlias for producing a blue or black variety." This 

 vision of a blue Dahlia is one that has haunted a certain class 

 of florists for a very long time. Such a flower would most 

 certainly be a great acquisition, and the wish to possess one of 

 that colour is rendered all the stronger by the almost utter im- 

 probability of its ever being gratified. 



The colours of flowers liave been divided by De Candolle 

 into two great classes, those having for their type yellow, which 

 passes into red and white, but never into blue, and those having 

 for their type blue, which passes also into red and white, but 

 never into yellow. This first series he calls xanthic, the last 

 cyanic, and of these Lindley has given the following analysis : — 



Of this classification a certain writer says, " It is found that 

 a yellow flower may assume the colours of the xanthic series, 

 but never become blue, and vice versa ; and this rule applies 

 to many genera. It is not, however, universal, as genera are 

 occasionally found having both yellow and blue flowers, as Tro- 

 pa'olum and Hyacinthus." The Dahlia belongs to the yellow 

 division, and it is very doubtful it ever it will prove another 

 exception to this all but general rule. 



With regard to a black variety, that is a colour which, with 

 two or three dubious exceptions, is all but unknown among 

 flowers, nor would it be appreciat-ed in a Dahlia otherwise than 



