BOTANY. 815 



c amphora very soon lose their vitality, and it is doubtful if they 

 would germinate after the lapse of time requisite to bring them to this 

 country ; but as the tree itself is so tenacious of life that to kill it is 

 a semi-impossibility, and as fine healthy plants are always readily 

 obtainable at Hong Kong or Amoy, there would be no difficulty in 

 introducing them here. 



Insect Powder. Persian Insect powder, which, when originally 

 introduced, consisted of the flower buds of Pyretlirum carneum and 

 P. roseunij as it occurs now consists in nine-tenths of the buds of P. 

 corymbosum W., the remainder being made up of other Pyrethra, P. 

 tenuifolium, or a variety of the P. corymbosum, partly of a Caucasian 

 variety of Anihemis arvensis. 



Similar properties belong to the flowers of Anthemis nobilis, Matri- 

 caria chamomilla, Achillea nobilis, Pyretlirum tanacetum, though in 

 a smaller degree. The age of these powders has great influence on 

 their efficacy ; they should always be as fresh as possible. 



Preservation of Cut Flowers. A recent English horticultural 

 writer gives the following information for prolonging the beauty of 

 cut flowers : 



" For keeping flowers in water, finely-powdered charcoal, in which 

 the stalks can be stuck, at the bottom of the vase, preserves them sur- 

 prisingly, and renders the water free from any obnoxious qualities." 

 When cut flowers have faded, either by being worn a whole even- 

 ing in one's dress, or as a bouquet, '-' by cutting half an inch from the 

 end of the stem in the morning, and putting the freshly-trimmed end 

 instantly into quite boiling water, the petals may be seen to smooth 

 out and to resume their beauty, often in a few minutes." Colored 

 flowers, carnations, azaleas, roses, and geraniums, may be treated in 

 this way; white flowers turn yellow; the thickest textured flowers 

 amend the most, although azaleas revive wonderfully. " I have seen 

 flowers that had lain the whole night on a table, after having been 

 worn for hours, which at breakfast next morning were renovated by 

 means of a cupful of hot water." Carnations and some others " keep 

 fresh after this treatment almost as long as they would have done if 

 they had been newly gathered." 



Benzine (Benzole) for Plants. The London Gardener's Chronicle 

 gives the following advice respecting the destruction of 'insects on 

 plants : " As our houses and gardens are always more or less infested 

 with vermin, it is satisfactory to know that benzine, an article be- 

 come sufficiently well known as a detergent, is no less efficacious as 

 an agent in insecticide. One or two drops are sufficient to asphyxi- 

 ate the most redoubtable insect pest, be it beetle, cockchafer, spider, 

 slug, caterpillar, or other creeping things. Even rats and mice will 

 speedily decamp from any place sprinkled with a few drops of the 

 potent benzine. 



To check the Warping of Planks. The face of the planks should 

 be cut in the direction which lay from east to west as the tree stood. 

 If this be done the planks will warp much less than in the opposite 

 direction. The strongest side of a piece of timber is that which in its 

 natural position faced the north. Dingler's Polytech. Jour. 



The Woods best suited for Ship-Building . At the last meeting 

 of the British Association (1861), Professor Calvert stated that he had 



