ART. II. Proceedings of Scientific Societies.

METEOROLOGICAL Society.-Dec. 13. Dr. Birkbeck, President, in the chair. Several highly interesting communications were read on the tremendous gale that visited this island on Nov. 29. last: the most important were from the Rev. W. B. Clarke of Poole; Captain W. H. Smyth, R.N., of the Observatory, Bedford; the Rev. W. T. Bree of Allesley Rectory, near Coventry; Mr. W. H. Campbell, Secretary to the Botanical Society of Edinburgh; and Mr. J. G. Tatem of High Wycombe.

From the manner in which the wind was observed to change its direction at various places during the gale, it was considered to belong to that class of hurricanes which traverse the western basin of the Atlantic. These hurricanes consist of a large body of air moving with considerable velocity round an axis which progresses in such a direction as to describe an elliptic or parabolic curve, the apex of the curve being situated about the parallel of the thirtieth degree of north latitude. It was requested that, on future occasions, observers would be careful to note particularly the phases of the storms, and the time when any change in the direction of the wind takes place.

The following extract from a letter from the Rev. W. T. Bree was then read: "On Oct. 11. last, between eight and nine, P. M., a bright band of light appeared in the sky, extending over the entire vault of the heavens, in the direction of s. w. by w. to N. E. by E. It was about as broad as a rainbow, and brightest at the south-western extremity near the horizon. In a quarter of an hour, or less, it had entirely, but gradually, disappeared." This phenomenon was seen by other gentlemen present; and Mr. Birt stated that he observed it at London. It appeared to him as an arch or band of light, similar to the auroral arches, much broader than a rainbow, and extending from one side of the horizon to the opposite. The stars it passed over were Capella, the Pole Star, ẞ Draconis, and Herculis. The position of these stars on the evening in question would give s. w. by w. to N. E. by E. as its direction as seen from London. It had a perceptible motion towards the south, and was visible about a quarter of an hour.

An interesting paper from the pen of Mr. Patrick Murphy (author of an excellent work on meteorology), anticipating the state of the weather during the approaching month of January, 1837, was next read. The author observed that the tendency of the weather throughout the month will be to drought; about

the 5th, if not earlier, frost may be expected to set in; and the greatest cold may be expected to occur in the night of the 13th, or morning of the 14th, succeeded by a thaw. From this period to the 22d, the weather will be squally, with rain; and this will be followed with frosty, dry, and harsh weather, till the end of the month.

It was suggested that meteorologists should rigorously observe the phenomena during the month, and accurately record their observations, and also report them to the Society, with a view to determine how far Mr. Murphy's "anticipations" may be proved to have been correct. At the next meeting, to be held on Jan. 10. 1837, Mr. Murphy will explain to the Society the courses of the late gales, their periodicity, and the method by which he prognosticates the changes of the weather for a period of twelve months in advance.

Mr. Birt (author of Tabule Anemologica) explained the principles of his method of registering the direction of the wind, and other meteorological phenomena, by which the curves of variation are delineated in a manner that is calculated to facilitate the comparison of the courses of the aerial current, either at distant points, or at periods long past. In the tables with which this method was illustrated, Mr. Birt directed the attention of the members to the circumstances that the curves presented similar portions, and that the same curves frequently reoccurred; thus indicating that the phenomena are of a periodical nature. As a remarkable instance of this, he observed that the same curve was described in June, 1833, and June, 1836, the weather on both occasions being similar.*

[Communications on subjects connected with meteorological phenomena, journals, &c., are requested to be addressed to the secretary, Mr. W. H. White, 4. Worship Square, London. - ED.]

ART. III. Literary Notices.

IN immediate preparation, a History of British Birds, in 2 vols., by Mr. Yarrell; and a History of British Reptiles, in 1 vol., by Mr. Bell. These works, with the British Fishes now finished, and British Quadrupeds now in course of publication, will complete a uniform series of the vertebrate animals of Great Britain, in 6 vols.

In the press, and will shortly appear, in one vol. 12mo, with numerous engravings, The Wonders of Geology, by Dr. Mantell, F.R.S. F.G.S., &c.

*We are indebted to Mr. White and Mr. Birt for the above report.

THE MAGAZINE

OF

NATURAL HISTORY.

FEBRUARY, 1837.

ORIGINAL COMMUNICATIONS.

ART. I. Remarks on a particular Form of Irritability observed in the Stems of many Plants, especially Exogens, evinced on dividing them in the Direction of their Axis. By Golding Bird, F.L.S. F.G.S., Lecturer on Experimental Philosophy at Guy's Hospital, &c.

WE are indebted to Dr. H. Johnson of Shrewsbury for the first notice of the very curious and interesting fact of the peculiar kind of vegetable irritability on which I am about to offer a few remarks. This gentleman observed that, "on dividing the stem of almost any herbaceous plant, a singular separation of the divided segments uniformly occurs; and that this separation continues until the stem withers and dies from the loss of its moisture." This discovery was made known by Dr. Johnson, in a memoir read before the Ashmolean Society of Oxford, and subsequently published in the Philosophical Magazine for March, 1835.

If a portion of the stem of an herbaceous exogenous plant, but especially those with fistulous stems, as any of the Labiàtæ, be divided longitudinally, in the direction of the axis of the plant, the division extending to the length of about 2 in., the divided portions will instantly separate from each other to the distance of 1 in., or even more; this separation constantly occurring, in whatever direction the plant may be held. The same thing occurs if the young shoots of woody stems are substituted for those more strictly herbaceous; the young branches of the common privet (Ligustrum vulgàre), as well as of the jasmine, and many others, possessing this property of diverging on being divided, in a remarkable

manner.

From a consideration of the facts thus briefly enumerated, Dr. Johnson was induced to attribute the cause of this diVOL. I. No. 2. N. s.

F

vergence to the vital irritability of the plants, in consequence of its absence in some which are very elastic, as in the rattan cane, and the dry and very elastic ligneous portions of the stems of plants. He appears to have been led to this conclusion from the apparent necessity of attributing this phenomenon either to the physical elasticity, or to the vital "contractility" (? irritability) of the plant itself; and, certainly, the fact of poisons preventing the developement of this divergent property appears to countenance this conclusion. But I think that the observations I am about to offer will be sufficient to show that this peculiarity may be explained on purely physical principles, independent of the necessary presence of vital agency; for I apprehend that, in vegetable as well as in animal physiology, it too often happens, that calling in the aid of vitality to explain secondary effects (independent of ultimate causes) is little else than, in other words, a confession of our ignorance.

I conceive that the separation of the divided portions of a stem may be explained on the same physical principles which Dutrochet has had recourse to, in his explanation of the irritability evinced by the valves of the seed-vessel of the Impàtiens Balsamina, and the pericarps of Momórdica Elatèrium. And here I may be excused a momentary digression, for the purpose of giving a very brief outline of Dutrochet's discovery. This philosopher has shown that, when a fluid, as water, or a weak saline solution, is enclosed in an organised membrane, as a piece of bladder, or placed in a glass tube over which a piece of membrane is firmly tied, and immersed in a solution of sugar, the bladder or glass tube becomes rapidly emptied; but if, on the contrary, the bladder or tube, be filled with syrup, and immersed in distilled water, the reverse takes place, the bladder becoming completely injected and turgid, and the tube filled with fluid; which, at last (if the tube be not too long), runs over. From these facts, amongst many others, M. Dutrochet was inclined to draw the following deductions:-1. That, when a fluid of low specific gravity, enclosed in an organic membrane, is immersed in one of greater density, the membrane becomes rapidly emptied, in consequence of a current being set up from the lighter to the denser fluid (from within and without); and, 2., that, when a dense fluid is enclosed in a membranous reservoir, and immersed in a fluid of a lower specific gravity, a current is set up, whereby the membrane becomes distended by a supply of fluid from without. The exceptions to these two rules are very few, and may at present be set out of the question. For the sake of convenience and conciseness of expression,

Dutrochet applied the term "endosmosis" to the current when established from within to without, and "exosmosis" when from without to within.

Having premised these remarks explanatory of the nature of endosmosmic action, I shall proceed to apply them to the explanation of the phenomena of divergence, commencing with a very brief account of some experiments which I performed with the hope of eliciting more information on this point.

1. A piece of the fresh stem of Lamium álbum was divided longitudinally, in the manner already described, to the extent of three quarters of an inch: divergence immediately ensued, the upper portions of the segments separating to half an inch. 2. Another piece of a similar stem was treated in the same manner, and its utmost extent of divergence ascertained. It assumed the appearance shown in fig. 8.

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9

It was then im

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mersed in distilled water: the divergence almost immediately increased; and in half an hour the segments had curved in opposite directions, like the zodiacal sign of Aries (fig. 9.)

3. The piece of stem used in the last experiment was removed from the water, and plunged into a weak solution of sugar in the course of an hour the segments had lost their curvature, and soon after their divergence, approaching so closely as to touch each other. (fig. 10.) By replacing the piece of stem in water, divergence again took place; and so on repeatedly,

4. A young plant of Làmium álbum was placed in a vessel containing water mixed with hydrocyanic acid, so that the roots and lower part of the stem were immersed in the poisonous mixture. In twenty-four hours the leaves appeared drooping, and even yellowish at their tips, and the stem flaccid; symptoms sufficiently indicative of the poisonous influence exerted by the hydrocyanic acid on the plant. The upper part of