THE MAGAZINE OF NATURAL HISTORY. JANUARY, 1832. ORIGINAL COMMUNICATIONS. ART. I. Remarks on the Luminosity of the Sea. By J. E. BOWMAN, Esq. F.L.S. THE valuable observations of Mr. Westwood on the luminosity of the sea (Vol. IV. p. 505.), induce me to think it worth while to place on record an extract from my private journal, which illustrates the view he has taken, and may possibly assist in establishing at least one cause of this well known and beautiful phenomenon. It is as follows: "On treading upon a tuft of tang [sea-weed] in our way down to the boat, it shot out in every direction interrupted rays of phosphoric light, like a star of artificial firework. This beautiful effect we repeatedly produced by stamping on various tufts to force out the water; and afterwards, while sitting in the boat, waiting for the ferryman, we amused ourselves by dabbling our hands and sticks in the water, which, when agitated, was more highly illuminated than I had ever before observed it. I was soon aware that the luminous matter lay upon the surface: for, after a little agitation and dispersion of the surface water from around my fingers, the effect was much diminished; and, when I ceased disturbing it, the light entirely disappeared. The boat swam, as it were, in a sea of liquid fire, the ripple round its sides and the dash of the oars being sometimes brilliant beyond conception, and of a bluish phosphorescent light. It would seem that the luminous matter was not equally diffused over the strait: for it varied much in intensity in different parts of the passage; and, as we approached the Caernarvonshire shore, the contact of the oars produced very little light.” VOL. V. No. 23. - B This extract refers to a passage across the Menai Strait, between Garth Ferry and Bangor, in company with my friend. Wilson of Warrington, about eleven o'clock in the evening of the 27th of July, 1830. The day had been very hot, the night was dark for that season, and the sea perfectly smooth and calm. I regretted that I had neither leisure nor opportunity to bring away some of the water for microscopical examination: but we had no phial at hand, and were quite exhausted with a long and difficult, though delightful, ramble over the sea rocks between Red Wharf Bay and Penmon Point, and thence to Beaumaris, along the loose sand and shingles of the coast; and were, besides, loaded with a rich harvest of plants, which required all our time and attention. But, though not then a stranger to the phenomenon, its singularly vivid appearance struck me forcibly; and I was quite convinced that the luminous matter floated, as it were, upon the surface like a thin coat of oil, for it was dispersed or repelled by the motion of a stick or the finger, and was confined to the circumference of an irregular circle around them. I can scarcely agree with Mr. Westwood that it is rendered visible by mere contact with the atmosphere, since it must always be in contact from its lying on the surface; yet we have abundant proof that it is only excited by disturbance. It struck me strongly, at the time, that it was elicited by friction, to which, I see, others have attributed it; yet it must be as sensibly alive to that agent as the iodide of nitrogen, for it was produced when I leaned over the boat and blew upon the water. It is a well known fact, that dead fishes and Mollúsca generate phosphorescence during the incipient stages of putrefaction; and chemical experiments have ascertained that it is increased, if it be not in some way caused, by the immersion of such substances in a solution of some neutral salt. In sea water, therefore, it is probably produced by muriate of soda [common salt]; and may not its situation on the surface be explained by its uniting with the oleaginous matter disengaged from decomposing animal substances, which, in a quiescent state of the sea, would rise and float like a film? I throw this out as mere conjecture, but it may help the philosophic enquirer to solve the problem. This luminous matter, however, which often marks the wake of a vessel in the night, and crests the waves with a splendour not their own, is certainly not the only kind of phosphorescence which the ocean exhibits. During the mild nights of summer and autumn, innumerable Medusa (the glowworms of the deep) may often be seen spangling its dark bosom, or lying on our shores, left by the receding wave. can never forget with what intense delight my friend Dovaston and myself once watched them glide past us on a midnight sail from Oban to Fort William; nor how willingly, in those regions of romance, philosophy alternately resigned her sway to the brownie or the kelpie. But I think, with Mr. Westwood, these "living fires of ocean" are not the primary cause of the phenomenon; and that, until some direct and well-conducted experiments establish the fact that their luminosity is an inherent and essential condition of their organisation, we may suppose it to be of the nature already mentioned, which may adhere to their surface as they swim among it, or may constitute their food; and, as such, be seen through their transparent substance: and, if friction be supposed necessary to exhibit it, this condition is probably fulfilled during the process of digestion and assimilation. One word more "on the suppositions that have been raised as to the objects of its existence." Those alluded to by your correspondent are, at least, unsatisfactory; and, as he has not given the ingenious and highly probable conjectures of Dr. Macculloch (Description of the Western Islands, vol. ii. p. 201.), I shall subjoin them. He supposes "the property of phosphorescence has been conferred on many fishes, and apparently in the greatest degree on the molluscous animals, whose astonishing powers of reproduction, and whose insensibility nearly approaching to vegetable life, seem to mark them as having been principally created for the supply of the more perfect tribes, to enable them to pursue their own prey, as well as for disclosing themselves to their pursuers, either during the darkness of the night, or in those deep recesses of the ocean impervious to the solar ray." He further adds: "The luminous property of dead fish is, perhaps, calculated for similar wise ends. These, sinking to the bottom, become capable of attracting the attention of the deep-water fishes; answering the double purpose of food to these tribes, and admitting the removal, as in the air, of carcasses which might produce, even in those depths, inconveniences similar to those which bodies in a state of putrefaction cause on the surface of the earth. It is also not improbable that the desire which fishes appear to show of following luminous bodies arises. from this natural instinct. Herrings are often caught in considerable abundance by a fly or any bright substance, often by new-tinned hooks, which they seize with great avidity. J. E. BOWMAN, The Court near Wrexham, Nov. 7. 1831. ART. II. Further Account of a Russian Natural History Expedition in Brazil, during the Seven Years preceding April, 1831. By M. F. FALDERMANN, Curator of the Imperial Botanic Garden, St. Petersburgh. Sir, (Continued from Vol. IV. p. 403.) IN the close of the communication which I made to you on April 18. 1831. (see Vol. IV. p. 403.), I promised to supply some account of the plants which M. Riedel brought alive from the Brazilian empire to the Imperial Botanic Garden: that promise I shall now endeavour to fulfil. On account of M. Riedel's uncommonly quick passage (namely, in sixty-four days) from Rio de Janeiro to St. Petersburgh, above two thirds of his plants were alive on his arrival at the Botanic Garden; and, in fact, were in a considerably better state than even many plants which we received from France and Great Britain: but we must in a great measure attribute this very successful transportation, considering the great many ineligibilities and inconveniences on board a ship on such a voyage, to M. Riedel's great exertions in attending the plants over sea. We must likewise remember the kind and obliging master of the vessel Captain Kromtschenko, who came with his cargo for the imperial Russian North-west American Company, from their colonies at Sitcha, and took charge of the plants at Rio de Janeiro; for the great care and assistance he bestowed on M. Riedel and his plants, he received from the Emperor of Russia a reward of 1000 rubles bco asig. (401. sterling), and it was mentioned in the public papers. I notice this only for the benefit of a great many other captains, who are usually by no means the most obliging persons to people at sea. The following is a list of the remarkable plants we received in the autumn of the year 1830, from the Brazils, into the Imperial Botanic Garden, as collected and brought home by the botanical traveller, L. Riedel : Acàcia amazónica Riedel. Bignonia, sp. from Rio Cássia, 3 sp. Acàcia, sp. Amaryllis, sp. Madera. Comaspérmum, sp. Coffea, sp. Crata va Tapia? Clusia, 2 sp. Cnemidóstachys, sp. Crìnum, sp. Carolínea, sp. Cecròpia, sp. Cissámpelos, 3 sp. Cóstus, sp. Cactus, 6 new sp. Euphorbia, sp. Márica, sp. Rhizophora Mangle. Roupala, sp. Solándra, 2 sp. Sapindaceæ, sp. Eupatorium Ayapana Francíscea uniflora. Magnolia,sp. (Talauma) Schnéllia, sp. Manihot, sp. (the true Solànum, 2 sp. Cassava of South Filices, 36 sp.; amongst dium sérra Fischer, Novum genus. Galipea, 4 sp. Seriàna, 2 sp. Scitamíneæ, 17 species; amongst which we had lately Phrýnium cylíndricum in flower. Seafórtia, sp. Terebintàceæ, 3 sp. Ternstræ mia, sp. Theobroma Cacao. Neóttia rufescens Fisch. Triópteris, 2 sp. Neóttia, 3 sp. Gouània, sp. Olyra, sp. Theophrásta, 2 sp. Guàrea, sp. Oxalis fruticosa. Trigònia glabra. Gesnèria, 3 sp. Gómphia, sp. Gambogia, sp. Geoffroya, 2 sp. Gardènia, 3 sp. Ionídium, 2 sp.. Joncquètia paniculata. Petrea volubilis. List of Palms brought at the same time, by M. Riedel, from The duty to which M. Riedel bound himself, during his travels in the interior of the Brazils, was, to collect for Russia, principally plants to form a Brazilian herbarium, and also as many seeds and live plants as possible for the Imperial Botanic Garden at St. Petersburgh. The principal of the conditions of his engagement was, to have a certain share of |