. Elements of botany. Botany; Botany. MINUTE STRUCTUKE OF LEAVES. 115 of leaf-surface in the two plants not too widely different. Calculate the area of the leaf-surface for each plant, by dividing the surface of a piece of tracing cloth into a series of squares one-half inch on a side, holding an average leaf of each plant against this and counting the number of squares and parts of squares covered by the leaf. This area, multiplied by the number of leaves for each plant, will give approximately the total evaporating surface for each. Water each plant with about all the water the earth will re
. Elements of botany. Botany; Botany. MINUTE STRUCTUKE OF LEAVES. 115 of leaf-surface in the two plants not too widely different. Calculate the area of the leaf-surface for each plant, by dividing the surface of a piece of tracing cloth into a series of squares one-half inch on a side, holding an average leaf of each plant against this and counting the number of squares and parts of squares covered by the leaf. This area, multiplied by the number of leaves for each plant, will give approximately the total evaporating surface for each. Water each plant with about all the water the earth will retain, then tie each pot up in a sheet of gum- rubber, such as is used by dentists, bring the rubber up about the stem and tie rather tightly, as shown in Fig. A thistle-tube, such as is used by chemists, is also to be tied in with the stem of the plant or (much better) at one side. The mouth of this should be kept corked when the tube is not in use for watering. Weigh each plant separately on a balance that is sensitive to one or two grams. Record the weights, allow the plants to stand in a sunny, warm room for 24 hours and re- weigh. Add to each plant just the amount of water which is lost," and continue the experiment in the same manner for several days so as to ascertain, if possible, the effect upon transpiration of varying amounts of water in the atmosphere. Calculate the average loss per 100 square inches of leaf surface for each plant. * It will be mucli more convenient to tie the hydrangea if one has been chosen that has but a single main stem. Instead of the hydrangea the common cineraria, Senecio cruentws, does very well. As its stem is too soft to be tied very tightly, it may be put in a glass battery jar covered at top with sheet lead slit to admit the stem and then brought together and sealed round the edges and next to the stem with grafting wax. 2 The addition of known amounts of water may be made most conveniently by measuring it in a cylindrical gradu
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1896
