46

PART II.

REVIEWS.

ART. I. A brief Account of Microscopical Observations made in the Months of June, July, and August, 1827, on the Particles contained in the Pollen of Plants; and on the general Existence of active Molecules in organic and inorganic Bodies. By Robert Brown, F.R.S. &c. [Not published.]

THIS little unpublished pamphlet, consisting of sixteen pages, has excited more curiosity at home and abroad than any thing we recollect for many years. It is the production of a gentleman who is acknowledged by every one to stand at the head of botanical science, and who deserves confidence for the correctness of his observations, and for the faithfulness with which he records them. His discovery is no less than this, that the ultimate particle he can obtain from all bodies, organic and inorganic, has inherent motion, like unto vital

action.

A discovery like this is not likely to be received without considerable scepticism: and hence we find one portion of the world believing by the exercise of faith; and another, by far the larger portion, doubting the existence of the facts, because their theories anticipate the laws of nature, and they have not patience to await for further information. No doubt microscopical observers, by seeking for magnifying power, and not for distinctness, are very subject to causes of illusion, and that many of the wonders which they have seen are to be referred to a lively imagination. Not so, however, the philosopher who now claims our attention. He is patient in observing, scrupulous in admitting, and faithful in recording, and, moreover, is borne out in his facts by a cloud of witnesses.

To make his observations, Mr. Brown employed a simple lens, the focal length of which was about of an inch, but he had recourse to much higher powers, to confirm them, and to investigate several minute points.

The several steps of the author's enquiry are more fully stated in his pamphlet than it is necessary to do here; but in

the month of June, 1827, he examined the grains of pollen belonging to the Clárkia pulchella, a plant just then brought from the north-west coast of America, by Mr. David Douglas, which grains, taken from the anthers full grown, but before bursting, were filled with particles, or granules, of unusually large size, varying from 0 to 3000 of an inch in length, and of a figure between cylindrical and oblong, perhaps slightly flattened, and having rounded and equal extremities. While examining these particles immersed in water, he observed many of them very evidently in motion; their motion consisting, not only of a change of place in the fluid, manifested by alterations in their relative positions, but also not unfrequently of a change of form in the particle itself; a contraction or curvature taking place repeatedly about the middle of one side, accompanied by a corresponding swelling or convexity on the opposite side of the particle. In a few instances the particle was seen to move on its longer axis. These motions were such as to satisfy him, that they arose neither from currents in the fluid, nor from its gradual evaporation, but belonged to the particle itself.

He extended his observations to many other plants belonging to the same natural family, namely Onagràriæ, and found the same general form and similar motions of particles: and, indeed, in all the different families he examined, particles were found varying in form from oblong to spherical, having manifest motions similar to those already described. In the grasses the membrane of the grain of pollen is so transparent, in some cases, that the motion of the particles within the entire grain was distinctly visible, and it was manifest also in some other plants. This is the first stage of his observations.

The second and most curious stage is, that in looking after these particles he saw others of a much smaller size, of a different shape, apparently spherical, and in rapid oscillating motion. These he denominates Molecules. He found them in the anthers of mosses, and on the surface of the bodies regarded as the stamina of Equisetum (Horsetail), and then in bruised portions of other parts of the same plants. He now thought he had got hold of the constituent or elementary molecules of organic bodies, first so considered by Buffon and Needham, then by Wrisburg with greater precision, soon after and still more particularly by Müller, and very recently by Dr. Milne Edwards. Following up this examination of organic bodies, he found the molecules to exist in various animal and vegetable tissues, whether living or dead; in gum resins, and substances of vegetable origin, such as pitcoal, and other mineralised vegetable remains. He then went

to decided minerals, and the first substance examined was a minute fragment of window-glass, from which, when merely bruised on the stage of the microscope, he readily and copiously obtained molecules agreeing in size, form, and motion, with those he had already seen. Metals, volcanic ashes, meteorites, rocks of all ages, granite itself, and, lastly, a fragment of the Sphinx in the British Museum, yielded the molecules in abundance. The dust, or soot, so miserably abundant in London, is entirely composed of these molecules, possessing visible, rapid, spontaneous, or inherent motion.

In many of the substances examined, especially those of a fibrous structure, such as Asbéstos, along with the spherical molecules other corpuscles were found, like short fibres, somewhat moniliform, whose transverse diameter appeared not to exceed that of the molecules, of which they seemed to be primary combinations. These fibrils, when of such length as to be probably composed of not more than four or five molecules, and still more evidently when formed of two or three only, were generally in motion, at least as vivid as that of the simple molecule itself; and which, from the fibril often changing its position in the fluid, and from its occasional bending, might be said to be somewhat vermicular.

In many instances oval particles were perceived, which seemed to consist of a simple combination, perhaps of two molecules, and these possessed a motion generally more vivid than that of the simple molecule; their motion consisting in turning usually on their longer axis.

The author is disposed to believe that the ultimate molecule, if we may so speak, is of uniform size in all bodies. Mr. Brown does not pretend that his facts relative to the particles of pollen are wholly original: but that still more curious (because more elementary and remote) existence of molecules in all organic and inorganic bodies, possessing an inherent motion, not to say voluntary; and, in simple combinations, a motion of two kinds at the same time (the one ambulatory, and the other on its own axis), is wholly, entirely, and undividedly his own.

No Englishman has dared to set up any claim to a fraction, not even a molecule, of this extraordinary discovery; and if there be those abroad, who now insinuate that the theories they have propounded to explain the motion of the particles of pollen, necessarily prove that they knew of, saw, and compassed these molecules, it only shows how much more importance they attach to theory than to experiment, and how little justice they are disposed to concede to an observer, who is behind none in doing justice to them.

O.

ART. II. Catalogue of Works on Natural History, lately published, with some Notice of those considered the most interesting to British Naturalists.

BRITAIN.

Stark, J.: Elements of Natural History, adapted to the present state of the Science. 2 vols. 8vo. 1/. 12s.

Transactions of the Linnean Society of London. Vol. XV. Part III. London. 4to.

Hewlett, Esther, now Copley: Scripture Natural History for Youth. London. 2 vols. 16mo, 82 plates. Bound in cloth, 12s.; with coloured

plates, 18s.

Quite a treasure for any deserving child, from six years of age to the time of teens." (Lit. Gaz.)

Trimmer, Mrs. M., Author of the Natural History of Man, &c.: A Natural History of the most remarkable Quadrupeds, interspersed with interesting characteristic Anecdotes. London. 2 vols. 12mo, 300 cuts. 8s.

ZOOLOGY.

The Zoological Journal, No. XIV. London. 8vo. Quarterly. 7s. 6d. plain; 10s. coloured.

The first paper is on the supposed identity of Whitebait and Shad, by William Yarrell, Esq. F.L.S. The diminutive fishes called whitebait have hitherto been generally considered as the young of the shad (Clupea Alòsa). Mr. Pennant gives the whitebait as an appendage to the bleak (Cyprinus albúrnus); and Dr. Shaw also describes the whitebait as a species of the Cyprinus, or carp genus. Dr. Turton, Mr. Donovan, and Dr. Fleming determine the whitebait to be the fry of the shad. Mr. Yarrell was first led to investigate this subject by observing the early appearance (March) of whitebait in a fishmonger's shop; and, knowing that shads, which they were supposed to be, did not make their appearance till much later (May), he took up and persevered in a course of investigation which lasted from March to August, 1828. The details we shall not enter into; but the specific distinction between the two fishes, on which he relies as of the greatest value, is the difference of their anatomical character, and especially in their number of vertebræ, "The number of vertebræ in the shad, of whatever size the specimen may be, is invariably fifty-five; the number in the whitebait is uniformly fifty-six; and even in a fish of two inches, with the assistance of a lens, this exact number may be distinctly made out." To show the value of this character as a specific distinction, he gives the following quotation from Dr. Fleming's excellent work on the Philosophy of Zoology, vol. ii. p. 311.: "The number of the bones of the vertebral column in different species of fishes being exceedingly various, suggested to Artedi the use of this character in the separation of nearly allied species. Among the species of the genus Cyprinus, for example, a difference in the number of vertebræ has been observed to the amount of fourteen. In ascertaining this character, Artedi recommends the greatest circumspection. The fish should be boiled, the fleshy parts separated, and the vertebræ detached from one another; and these counted two or three times in succession, to prevent mistakes. This character is of great use, as it is not liable to variation; individuals of the same species exhibiting the same number of vertebræ in all the stages of their growth."

The other new facts in this and preceding numbers of the Zoological Journal will be found in due time among our Collectanea,

The Zoological Periodicals.

Curtis's British Entomology, No. LXII., for February (Mag. Nat. Hist. vol. i. p. 54.). Stephens's Illustrations of British Entomology, No. XXIII., for February (Mag. Nat. Hist., vol. i. p. 55.). Sowerby's Genera of Recent and Fossil Shells, No. XXXI. (Mag. Nat. Hist., vol. i. p. 56.).—Sweet's British Warblers (Mag. Nat. Hist., vol. i. p. 57.) is completed in one volume 8vo, 16 col. pl., 16s. 6d. This is a very handsome work; the plates are from living specimens in the author's collection," including the nightingale, redstart, blackcap, whitethroat, garden warbler, and all the interesting birds of passage belonging to the genus Sylvia, which contains the choice singing birds that visit this country; with a full account of the author's method of treating them, in which is shown how they may be kept in confinement in as good health as any common bird whatever."

The Tower Menagerie; comprising the Natural History of the Animals contained in that Establishment, with Anecdotes of their Characters and History. Illustrated by Portraits of each, taken from life, by William Harvey, and engraved on Wood by Branston and Wright. London. 8vo.

The wood engravings which illustrate this work are equal, if not superior, to any thing which has appeared since the invention of the art; and they show how extensively, and with what advantage, that description of illustration may be employed in natural history. Much of the effect of a wood engraving depends on the paper on which the impression is taken, and on the care and skill of the pressman. In the present work every possible care seems to have been taken in these respects; and, in consequence, one of the most elegant octavo volumes has been produced which ever issued from the British press. The literary matter is also highly entertaining and instructive. The history of sixty wild animals, including some birds and serpents, is given; and, in the introduction, is ably and elegantly traced the origin and progress of menageries. Menageries date from the most remote antiquity, and are alluded to even in the obscure traditions of fabulous ages. The barbarian warrior sought amusement in the chase, and treasured up his spoils in common with the trophies of battle. Afterwards the strength and ferocity of the brutes of the forest were rendered available as auxiliaries in war; and the animals so employed were confined in what may be considered as menageries.

Many wild animals occupied a distinguished place in the theology of the dark ages: they were either worshipped or sacrificed, and for these purposes must have been preserved in some sort of menagery. The domestication of animals may be considered as having taken place by similar means; and fields and stables, and their inhabitants, only differ from the apartments for wild animals in containing those which minister to necessity and convenience, instead of curiosity and science. Aristotle's History of Animals is materially indebted to the menagery formed in civilised Greece by the Macedonian conqueror, on his return from India. The Romans had first menageries for the use of the public amphitheatres, and afterwards vivaria of rare and curious animals, for the gratification of naturalists. The first establishment of this kind, in modern days, was that founded at Versailles by Lewis XIV., and to that we owe the Natural History of Buffon. The first notice of a royal menagery in England relates to a collection of lions, leopards, and other strange beasts, kept at Woodstock by King Henry I. From Woodstock they were transferred to the Tower, and the Sheriffs of London, Bedford, and Buckingham, of this and succeeding reigns, had orders to maintain these animals and their keepers. "In 1252, the Sheriffs of London were commanded to pay four-pence a day for the maintenance of a white bear; and, in the following year, to provide a muzzle and chain