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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



of savants ; at the same time it is influenced by external causes which are 

 easier to determine. Thus in autumn, during the pericd of rest, the bud 

 of a tree is formed from internal causes inherent in the vegetable nature ; 

 but until the following spring external influences (cold, for example) act 

 upon it, so that it does not stir, but remains inert. If at the same time of 

 year this external action be removed, either from the cessation of the 

 cold or from our placing the bud in a warm room, it will awake little by 

 little and begin to push. 



It is generally known that if a tree, for any reason, has lost its leaves 

 in the summer its buds, which in the ordinary way would not push until 

 the following spring, sometimes develop during the autumn. It is thus 

 that you often see certain Lilac bushes flower again in the month of 

 An 'j ust, and perhaps more frequently Horse Chestnuts in September. In 

 these cases the buds have not yet come to a state of complete rest when 

 they are set pushing. Nevertheless this does not happen (save in ex- 

 ceptional cases) with a tree that has kept its leaves until the middle of 

 the autumn. In this case the buds have had time to enter into a state 

 of absolute rest, as far, at least, as it is permissible to employ the word 

 absolute in such a sense. On the other hand, the nearer the period of 

 rest approaches its end, the more easily will the flower buds develop 

 themselves. 



From these considerations the Danish savant establishes three 

 divisions during the period of rest, perhaps seme what artificial : initial 

 rest, complete rest, and final rest. In the first stage the faculty of 

 development diminishes more and more ; in the second it no longer exists ; 

 in the third it returns by slow degrees. Well, then, if a very severe 

 drought occurring in the middle of the summer or intense cold arriving 

 in the autumn can produce in the growth of trees or shrubs a complete 

 check, or a still more pre found state of rest, ether can also produce the 

 same result ; and etherisation has exactly the same effect in modifying 

 the natural development of the plant, and the result resembles that 

 which one observes in the open air in a tree that for some reason or 

 other has lost its leaves early, viz. an abnormal and precocious growth. 

 It may be supposed that flower-buds from their formation until the first 

 ya of September are in the first stage of rest; the second lasts from 

 then until the end of October ; from this time the third stage begins, 

 and during the month of January comes to an end : the buds have 

 virtually come out of their state of repose, or are only retained in it by 

 the influence of the cold. It was during the first and last stages that 

 the specimens of the Lilac' Charles X.,' treated with ether, were brought 

 into growth with a rapidity that was remarkable. 



We now come to the working methods used by Dr. Johannsen. In a 

 box capable of being hermetically closed were placed the shrubs to be 

 <-\p» riinented on. The plants, as dry as possible, were planted in a bed 

 of equally dry sand. A moist soil or moist sand absorbed a certain 

 amount of ether, and the effect of this, it was found by experience, was 

 to diminish its action, or even, if the ether penetrated to the roots, to 

 danmu'< theni. The temperature in the box ought to be about 17' to 

 I 1 ' 0. (02 to 66 P.) At a higher temperature a less quantity of ether 

 would be sufficient, but concerning its action at low temperatures we are 



