. Chambers's miscellany of useful and entertaining tracts. g open.^The accompanying figure represents a leaf of the nepenthes, with ~ its curious appen-dage and fittings,than the structureof which nothingcould be more tlio-roug^hly adaptedfor accomplishingthe end in this head may be mentioned the shea, or butter tree,from the kernel of which the Africans extract a fatty substancethat is whiter, finer, and equal in flavour to the best butter madefrom cows milk, with this advantage, that it will keep withoutsalt for many months; the tallow tree, or candleberry myrtle,the nut of which
. Chambers's miscellany of useful and entertaining tracts. g open.^The accompanying figure represents a leaf of the nepenthes, with ~ its curious appen-dage and fittings,than the structureof which nothingcould be more tlio-roug^hly adaptedfor accomplishingthe end in this head may be mentioned the shea, or butter tree,from the kernel of which the Africans extract a fatty substancethat is whiter, finer, and equal in flavour to the best butter madefrom cows milk, with this advantage, that it will keep withoutsalt for many months; the tallow tree, or candleberry myrtle,the nut of which yields a waxy substance used in the manufac-ture of candle in America; the India-rubber tree, from thethickened juice of which caoutchouc is obtained; the bread-fruit;and many others; but as these have been noticed in variouspopular works, and as our space is limited, we pass on to thecurious phenomena of HEAT AND LUMINOSITY IN PLANTS. We are aware that warm-blooded animals have the power ofkeeping up a certain temperature within them, which varies at 27. CURIOSITIES OF VEGETATION. certain stages of their growtli, and perhaps periodically. Thisresult is obtained by respiration—the oxygen of the atmosphereuniting with the carbon of their blood, and producing a speciesof combustion. The more fresh air we breathe, the greater theheat of our bodies, so long as we take proper food to afford thecarbon. A similar though less understood phenomenon seems totake place in the respiration of plants. Heat is always disen-gaged when gaseous products are liberated; and as vegetablesrespire, however slowly, a certain degree of heat must be pro-duced during that process. In germination, heat is sensiblyevolved: a piece of ice placed on a growing leaf-bud dissolves,when it would remain unchanged in the open air; and experi-ment has proved that the surface of growing plants is three orfour degrees higher than the surrounding medium. Again, theinternal temperature of a large trunk is always high
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Keywords: ., bookauthorchambers, bookcentury1800, bookdecade1850, bookyear1854
