ART. X. Sir, On some Phenomena attending Sphæria fraxinea. THE specimen which I enclose for your inspection, I believe to be one of the Sphæ`ria fraxínea (fig. 47.), class Cryptogàmia, order Fúngi, L. Unfortunately, I have not turned my attention to this tribe of plants; and I possess only the edition of 1792 of Withering's Botanical Arrangement ; I am therefore unable to determine whether this subject has now another generic name. Be this as it may, the annexed description is decisive, I think, of the identity of the fungus. "Sphæ`ria fraxinea. Roundish, convex, black, dotted, nearly sitting, pustular. 'Convex without; substance within consisting of a number of concentric layers, composed of minute tubes, or threads, pointing from the centre. Substance hard; covered with a thin bark, of a brownish black, somewhat wrinkled and rather glossy, grey within.' (Ray.) Very irregular in shape, from one half to more than an inch in diameter. Pustules scarcely visible to the naked eye.' (Rehl. Supp., i. 34.) This, which is very common, differs from the S. máxima, in being more woody, and showing concentric circles when cut. It is generally more completely sessile than it is represented in the figures. "Lycoperdon fraxíneum of Huds., &c. Sphæ`ria concéntrica Bolt. On ash trees when rotten, or in a decaying state, and observed on no other tree." (Ray.)- With., vol. iii. 475. It is not on account of the mere curiosity of the species that I now send it to you, Sir, although I am acquainted with but one little, old, ash tree, in a state of decay (and that nearly four miles from my residence), which produces these Sphæ riæ from between the interstices of the bark; but from the singular phenomena which it exhibited during eight or ten nights successively. Three or four of these Sphæ`riæ were brought home one morning, and placed on the mantle-shelf: they were regarded at first as curious, and somewhat ornamental productions of nature; but when I entered the parlour on the following morning, I was struck with surprise at finding each of them surrounded with a black powdery efflorescence (fig. 48.), dense edges well defined near the fungus, but gradually shaded off, and somewhat radiated. Underneath, there was not the slightest particle of powder; but the whole convex surface of each was covered with a powdery mass, or stra tum, of a fine bluishblack colour, which was readily brushed off with a feather; in fact, from ten or twelve of these fungi, I collected dust enough to form, when ground up with mucilage of acacia gum, a small cake of colour, with which the accompanying specimen was etched with a crow-quill. By repeated observations, I found that the radiation took place only in the night; never between the hours of 10 A.M. and 5 P.M., but constantly after the evening had closed. Connecting this fact with other natural phenomena, I am inclined to ascribe the process to electrical agency; I believe it to depend upon that ascending current of electricity, which is evidently in a state of peculiar activity during the night, and is the origin of several marked phenomena; among others, I little doubt, that of the diffusion of odour from the corollas of night-smelling plants. I hope soon to invite your attention to the phenomena of the descending day-current of solar electricity, and the ascending night-current, just alluded to; but the subject would be premature on the present occasion. In the instance of this curious fungus, I think it philosophically just to enquire, whether or not the peculiar season of the last year, 1828, might not produce effects very different from those attendant upon ordinary seasons. From the 18th or 19th of March, the whole spring and the greater part of the summer appeared to be governed by electrical inductions; and it is possible that many phenomena may have depended solely upon those inductions, and therefore may not occur again. If I live, I mean to pay close attention to this fungus, and report the result faithfully and particularly, should you see fit to honour this communication so far, as to insert it in your Magazine. In the meantime, I state the following general facts. The specimens now sent were gathered about the middle of May; the one which much resembles an insect of the coleopterous tribe, was that which produced the efflorescence on the piece of paper accompanying it; it had been at work several nights before I laid it on the paper, and the writing was added at the very time stated. The other two specimens are sent merely as such; and one is divided to exhibit the concentric layers and radiations of the internal structure. No efflorescence proceeded from these layers of the inside, nor was that from the exterior surface much disturbed or prevented by the section. I am inclined to ascribe the effect to electricity as its ultimate cause, in this particular instance; because, I think, the separation of the fungus from its natural bed (the bark of the ash) might interrupt the regular current, and produce anomalous effects. Nevertheless, as vegetable electricity is governed by specific laws, which exert different energies at different periods, I conceive, that, although the ascending night-current might be thus interrupted, the state of the atmosphere might induce chemical affinities, by which the aqueous juices of the fungus were decomposed, and sufficient heat developed to produce radiation. Some such internal action must have been induced, and that, too, by an energy which was not in action during the day. Light must have been antagonist to it; for the effect was never discerned till towards the hour of sunset, and it ceased with the return of day. I am inclined to ascribe the phenomenon secondarily to the decomposition of water; because the radiation ceased when the fungus became dry, and was renewed, though only in a very slight degree, by immersion in water. I am, Sir, &c. Grove House, Dec. 26. 1828. ELECTRICUS. ART. XI. Some Account of a remarkable Spruce Fir Tree in the Woods at Bruco Castle, Perthshire. By Mr. ARCHIBALD GORRIE, C.M.H.S. Sir, THE luxuriance of the Indian banyan tree (Ficus índicus) attracts the notice, and excites the astonishment, of European travellers. This plant, in common with many of the genus Ficus, readily emits roots at the joints of the young wood; the young side-shoots are pendulous, and on reaching the ground they readily strike root under the genial climate, and in the rich soil, of Hindoostan. The plants which compose the genus Pinus are, for the most part, more difficult to raise by layers or cuttings than those of any other genus of trees which abound in our northern forests; and yet it is among the pine tribe that the nearest approach is made to the Indian banyan. A beautiful tree of the black American spruce (Abies nigra), 49 about forty years old, stands in the woods at Braco Castle, Perthshire, the property of James Masterton, Esq., of Braco; from its side-shoots a number of young trees have sprung up of different altitudes around the mother-plant. The circumference is regularly and gradually extending, and fresh shoots strike root and grow perpendicularly all around the original plant. Should this beautiful assemblage of evergreen spires be allowed to extend, and be protected from the inroads of cattle, it may be difficult to assign limits to the beautiful mass of vegetation which time may form. The above sketch (fig. 49.) will give some idea of its present appearance. It may be proper to add that a natural seedling from this tree, standing not far distant from the mother-plant, apparently about twelve years of age, is also in its turn already surrounded by a numerous and healthy rising family. Both these trees were pointed out to me by Major F. H. Elliot, Royal Engi neers, and the proprietor, Mr. Masterton, as natural curiosities. I am, Sir, &c. ARCHD. GORrie. Annat Gardens, near Errol, Perth, March 10. 1828. ART. XII. Of Winds, and the Causes of their different Kinds. By Mr. MAIN. It has been stated by Dr. Birkbeck as his opinion, that not only the causes of wind will be better understood, but also the time of its happening in any particular place be predicted with certainty. This would be a wonderful, as well as useful, portion of human knowledge. Such foresight would regulate much of the open-air business of life; in assisting to preserve the fruits of the earth; and, in an infinite degree, to influence the movements of the mariner. Considerable advances have been made in this science in intertropical climates, where the sun exerts so much power. There the prevailing winds are generally, or partially, periodical. In the central parts of the Atlantic, Pacific, and Indian oceans, where the currents of the atmosphere are not disturbed by the influences of land, the winds, if any at all, blow constantly from east to west, or from the collateral points. This is caused by the cooler air of evening pressing westward upon the heated air of mid-day; in other words, the lower temperature of the air in the place to the eastward of the sun, causes it to press westward upon the rarefied air at the place over which he is vertical. This general breeze, in that part of the Indian ocean which washes the southern shores of Asia, is broken into varying, though nearly periodical currents, called monsoons. These winds, and their changes, have been rationally accounted for, by attributing their deviations from the general current met with ten degrees to the southward of Ceylon, to the influences of the more rarefied state of the air, over the peninsulas of hither and farther India; and also to the sun's motion in the ecliptic, which, in some measure, causes those seasonal influences. It is now a well established fact, that the exciting cause of all currents of air is before, and not behind, the blast. This is daily exemplified in warm countries on the sea-shore; for when the unclouded sun has risen about four hours, and has heated the land to a higher temperature than the sea, imme |