Page:Popular Science Monthly Volume 19.djvu/105

Rh however, which can not perhaps be dwelt upon too much, and that is the value of this genus of plants as drainers of the soil and purifiers of the atmosphere. This is probably the true reason why so many attempts, more or less successful, have been made to acclimatize the eucalyptus in Southern Europe and even in Great Britain. No doubt, experiments have been stimulated by other causes. The foliage of these trees is, for example, unlike that of any other in our islands. It is pendulous, quivering, and evergreen; and the peculiar whitish appearance of one side of the leaves—due to a fatty or resinous secretion—is very characteristic. Till the tree is from three to five years old, the leaves grow horizontally; but afterward they generally assume a pendent position. Instead of having one of their surfaces toward the sky, and the other toward the earth, they are often placed with their edges in these directions, so that each side is equally exposed to the light. This arrangement may have something to do with the extraordinary quantity of moisture these trees exhale into the atmosphere.

The eucalyptus belongs to the natural order Myrtaceæ, and is indigenous to the temperate parts of Australia (where it goes by the name of stringy-bark, or gum-tree) and Tasmania—that is, where the mean temperature does not exceed a range of from 52° to 72° Fahr. The foliage is leathery, and almost always characterized by a certain metallic aspect. The leaves are as a rule narrow, and have either a very short and twisted petiole or foot-stalk, or none at all. In Australia they commonly attain a height of two hundred feet, and instances are given in which a height of three hundred and fifty feet has been attained. The flowers are usually pinkish or white, and in the latter case superficially resemble those of the myrtle. Unlike these, however, they are devoid of petals. The fruit contains the seeds—seeds so minute, it is said, that from one pound of those of the variety Globulus more than one hundred and sixty thousand plants could be raised.

I have always taken a great interest in the eucalyptus, and have grown it near Dublin for several years with considerable success. I have had at one time as many as twenty fine healthy saplings of the species Globulus, of from ten to sixteen feet high, and one which reached to twenty-five feet, and had a stem of twenty-two inches circumference. These were all five years old. But cold is the deadly enemy of the gum-tree; and, though I had kept mine during four ordinary Irish winters, I lost them all during the almost Arctic winter of 1878-'79. I may say, in passing, that I have not been quite discouraged, and that I have again several healthy plants making good progress. My interest in the subject has received a new stimulus from a recent experience of eucalypt-culture in the wild plain known as the Campagna of Rome.

One lovely morning in last October we left our hotel hard by the