The Climate.-We have complained much of the rain, which we can truly say fell more or less every day during the month that we were at Crosslee Cottage, and the two or three days that we remained in Glasgow; but it appears from the following communication, received from a gentleman on whom we can depend, that the climate is by no means so moist as is commonly thought. "You say that the 'trees, &c., are rarely seen in a thriving state,' which you attribute to some other cause than the lodgement 'of the earthy part of the smoke on the leaves,' because, &c., and here you cannot resist the old answer to the question, Does it always rain ? 'No, it sometimes snaws (snows).' Now, in 1841, we had 143 fair days, 66 cloudy, 41 stormy, 76 rainy, 41 showery, and 12 snowy. But, in as far as the fuliginous particles are concerned in not injuring the trees, you are quite correct, even without their being washed off, thus evidencing in some degree their innocuous quality; because upon the south side of the river even the Pinus sylvestris thrives amidst a perfect Pandemonium of smoke, arising from the coal and iron-works in that neighbourhood: but there exist no chemical factories on the south, unlike in that respect the north bank of the Clyde, where these exist in great number; the acidulous emanations from which, even at the distance you mention, wither up the leaves in the course of a few hours; thus, during summer, the leaves of the common lilac, in front of my house, fell off and were renewed two or three times, or, in other words, as often as the wind blew from that quarter; eventually the twigs became dried up, then the branches, and finally the trunk itself. "Whilst on this subject, I may mention a fact which I cannot sufficiently explain upon physiological principles, and I shall be glad to be gratified in your continuation in March next, viz. that those plants and trees whose habitat is either alpine or maritime, such as the thrift, Armeria, the saxifrages, particularly the S. umbrosa (London pride), the birch, &c., flourish most luxuriantly even in the midst of those chemical emanations.-S. Jan.27. 1842." Probably the leaves of alpine plants may have fewer stomata than those of plants which grow on plains, and hence may be less affected by changes of air than those which have numerous stomata. They may thus thrive in an atmosphere impregnated with salt, and also in one impregnated with soot. This, however, is mere conjecture. (To be continued.)
