thoroughly wet, but the conclusions of this eminent physicist appear to have been generally accepted until the very careful experiments of Mathieu at the Forest-School of Nancy were made known. The observations of Mathieu were made in a plantation of deciduous trees forty-two years old, and were continued through the entire years 1866, 1867, and 1868. The result was that the precipitation in the wood was to that in an open glade of several acres near the forest station as 043 to 1,000, and the proportion in each of the three years was nearly identical. According to Mathieu, then, only 57 thousandths or 5.7 per cent of the precipitation is intercepted by trees.--Surrell, Etude sur les Torrents, 2d ed., ii., p. 98. By order of the Direction of the Forests of the Canton of Berne, a series of experiments on this subject was commenced at the beginning of the year 1869. During the first seven months of the year (the reports for which alone I have seen), including, of course, the season when the foliage is most abundant, as well as that when it is thinnest, the pluviometers in the woods received only fifteen per cent less than those in the open grounds in the vicinity.--Risler, in Revue des Eaux et Forets, of 10th January, 1870.] while in heavier rains, the large drops which fall upon the leaves and branches are broken into smaller ones, and consequently strike the ground with less mechanical force, or are perhaps even dispersed into vapor without reaching it. [Footnote: We are not, indeed, to suppose that the condensation of vapor and the evaporation of water are going on in the same stratum of air at the same time, or, in other words, that vapor is condensed into rain-drops, and rain-drops evaporated, under the same conditions; but rain formed in one stratum may fall through another, where vapor would not be condensed. Two saturated strata of different temperatures may be brought into contact in the higher regions, and discharge large rain-drops, which, it not divided by some obstruction, will reach the ground, though passing through strata which would vaporize them if they were in a state of more minute division.] The vegetable mould, resulting from the decomposition of leaves and of wood, serves as a perpetual mulch to forest-soil by carpeting the ground with a spongy covering which obstructs the evaporation from the mineral earth below, [Footnote: The only direct experiments known to me on the evaporation from the SURFACE of the forest are those of Mathieu.--Surrell, Etude sur les Torrents, 2d ed., ii, p. 99.