1806.] Critical Catalogue. 279

in autumn, and are leſs ſubje& to be injured by the winter's cold. It is doubtfal whether this be a ſeminal diſtindion or an accidental variety; but ſuch forward plants have always the bark of their young ihoots of a dull purple colour. In planting oaks, it would be proper ro chóofſe theſe till the matter be better kuown. The oak tree in coppices, and alſo the mountain aſh, is valuable, on account of the bark; much demanded for tanning leather, and now is ſold at 14. per ton. The bark of the ſállow and birch are uſed for the ſame purpoſe, and ſold_at half that price. The value of oak timber is well known. Though its growth is ſlow in infancy, when it is placed in 2 favourable ficuaiion, it will make a progreſs in the courſe of fifty years, little inferior to many o'her kinds, and arrive at length to a great ſize. Among the oaks of Hamilton-park(the pro- perty ot the Duke of that name), ſo famous down to the end of the ſeventeenth century. there were trees which meaſured twenty-ſeven feet round the trunk, with 2 wide expanſe of branches,

« The horſe cheſnut tree thrives well on the lower grounds, and deep ſoil only. The ſweet cheſaut, which quickly becomes a timber tree in diſtrits more northern, does not ſucceed here. Its ſeaſons of growth are too early, or too late, for the climate. In its firſt, it bears ſome reſembiarce to the Siberian pine,&c.; 1n its laſt, to the oak; its early growths being almolt as early as thé former, and its latter being nearly as late as thoſe of the latter, and fill more ſofr and ſuſceptible of the cold. Hence its ſhoots arc alternately put forth and deſtroy=d, and it generally becomes a low ſtanted ſhrub. Bat this does not ſeem to have always been the caſe. There was in the lower part of the pariſh of Cambuſnethan, on the grounds of Mr. Lockart, of Cafſlehill, a tree of this kind, magnificently branched, and of a very large ſize, the ſtump ot which ſtill remains living. This ſeems to be a preſumption of the conje&ure advanced in the former part of this Report, that the natural accretion of flow moſſzs tended to increaſe the inclemency of the neighbouring climate; ſince the annual addition which cheſe moſſes viſibly ac- quire, in a diſtri where they abound ſo much, may, in the courſe of two or three centuries, come to ſuch an amount as to produce 2 ſenſible change in the ſtate of‘the air; while in diitri&s where the extent of moſs is inconſiderable, uch effedâs do not take place.‘The fate of the walnut, which may be confidered as much a timber tree as a fruit one, is nearly the ſame with that of the ſweet cheſnut.

«The poplar delights moßt in water-formed ſoils, but 1s averſe to marſh, and, when happily ſituated, makes quicker progreſs than any other tree. This county has been long in poſſeſſion of two kinds of the white poplár, equally ſacceſsfal. Diſtinguiſhing chem by their habits, they may be called the towering and the branching. The Lombard poplar, which, it has been ſaid, becomes a large tree be- ſouth the Trent, makes here but poor advances to timber. The

balſam poplar makes very great progreſs.

< In general, all the ſoils which lie immediately over the freeſtone rock, are much diſpoſed to produce wood, and almoſt all kind: of trees thrive in them. Land lying on a quick declivity, where the water iffuing from the veins of the earth lows freely away, is very favourable to the growth of wood. For this reaſon, trees grow bet- {er on the dip than on the crop of the mineral lirata.‘Trees,