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THE EDINBURGH JOURNAL OF NATURAL HISTORY. 



forded me when at Cavite, near Manilla, in 1830, of witnessing, for the first time, 

 tiiis beautiful scene. As far as the eye could reach over the extensive bay of Manilla, 

 the surface of the tranquil water was one sheet of this dull, pale phosphorescence ; 

 and brilliant flashes were emitted instantly on any heavy body being cast into the wa- 

 ter, or when fish sprang from it or swam about. The ship seemed, on looking over its 

 side, to be anchored in a sea of liquid phosphorus, whilst in the distance the resem- 

 blance was that of an ocean of milk. 



*' The night to which 1 allude, when this magnificent appearance presented itself to 

 my observation, was exceedingly dark, which, by the contrast, gave an increased su- 

 blimity to the scene. The canopy of the heavens was dark and gloomy, not even the 

 glimmering of a star was to be seen ; while the sea, of liquid fire, cast a deadly pale 

 light over every part of the vessel, her masts, yards, and hull; the fish, meanwhile, 

 sporting about in numbers, varying the scene by the brilliant flashes they occasioned. 

 It would have formed, I thought at the time, a sublime and beautiful subject for an 

 artist like Martin to execute, with his judgment and pencil ; that is, if any artist could 

 give the true effect of such a scene, on which I must express some doubts. 



*' It must not be for a moment conceived that the light described as brilliant, and 

 like to a sea of ' hquid fire,' is of the same character as the flashes produced by the 

 volcano, or by lightning, or by meteors. No ; it is the light of phosphorus, as the 

 matter truly is pale, dull, approaching to a white or very pale yellow, casting a me- 

 lancholy light on objects around, only emitting flashes by collision. To read by it is 

 possible, but not agreeable; and, on an attempt being made, it is almost always 

 found that the eyes will not endure the peculiar light for any length of time, as head- 

 aches and sickness are often occasioned by it. I have frequently observed at Singa- 

 pore, that, although the tranquil water exhibits no particular luminosity, yet, when 

 disturbed by the passage of a boat, it gives out phosphoric matter, leaving a brilUant 

 line in the boat's wake ; and the blades of the oars, when raised from the water, seem 

 to be dripping with Uquid phosphorus. 



*' Even between the tropics, the phosphoric light is increased cr diminished in its 

 degree of brilliancy, in a very slight difi^erence of latitude ; on one day it would be seen 

 to a most magnificent extent, on the next it would be perhaps merely a few luminous 

 flashes. It might proceed from the shoals of mai'ine animals, that caused the bril- 

 liancy, to be less extensively distributed over one pai't of the ocean than another. That 

 I am correct in asserting that some of the animals which occasion the phosphoric light 

 emitted by the ocean do travel in shoals, and are distributed in some latitudes only 

 in a very Umited range, I insert two facts which occurred during this voyage, and 

 which will no doubt be regarded as mteresting. 



*' On the 8th of June, being then in latitude 00° 30' south, and longitude 27° 6' 

 west, having fine weather and a fresh south-easterly trade wind, and range of the ther- 

 mometer being from 78° to 84°, late at night the mate of the watch came and called 

 me to witness a very unusual appearance in the water, which he, on first seeing, con- 

 sidered to be breakers. On arriving upon the deck, this was found to be a very broad 

 and extensive sheet of phosphorescence, extending in a direction from east to west as far 

 as the eye could reach ; the luminosity was confined to the range of animals on this 

 shoal, for there was no similar Hght in any other direction. I immediately cast the 

 towing net over the stern of the ship, as we approached nearer the luminous streak, to 

 ascertain the cause of this extraordinary and so limited a phenomenon. The ship soon 

 cleaved through the brilhant mass, from which, by the disturbance, strong masses of 

 hght were emitted; and the shoal (judging from the time the vessel took in passing 

 through the mass) may have been a mile in breadth ; the passage of the vessel through 

 them increased the hght aroxmd to a far stronger degree, illuminating the ship. On 

 taking in the towing net, it w^as found half-filled with Pyrosoma fAtlantzcumJ, which 

 shone with a beautiful pale greenish hght; and there was also a few small fish in the 

 net at the same time. After the mass had been passed through, the light was still seen 

 astern, until it became invisible in the distance; and the whole of the ocean then bo- 

 came hidden in darkness as before this took place. The scene was as novel as it was 

 beautiful and interesting, more so from ha\'ing ascertained, by capturing the luminous 

 animals, the cause of the phenomenon. 



" The second was not exactly similar to the preceding; but, although also hmited, 

 was curious, as occurring in a high latitude during the winter season. It was on 

 the 19th of August, the weather dark and gloomy, with light breezes from >'orth- 

 north-east, in latitude 40° 30' South, and longitude \3&° 3' East, being then distant 

 about 368 miles from King's Island (at the western entrance of Bass's Straits). My 

 journal remarks the atmosphere to have been very chilly during the day, but much 

 milder in the evening; the range of the thermometer during the day being from 49° 

 to 56°. It was about eight o'clock p.m. when the ship's wake was perceived to be 

 luminous, and scintillations of the same light were also abundant around. As this 

 was unusual and had not been seen before, and it occasionally also appeared in laro-er 

 or smaller detached masses, gi^'ing out a high degree of brilliancy, to ascertain the 

 cause, so unusual in high latitudes during the winter season, 1 threw the towing net 

 overboard, and in twenty minutes succeeded in capturing several Pyrosoma^ givin"- 

 out their usual pale green light ; and it was no doubt dt:tached groups of these ani- 

 m^ds that were the occasion of the light in question. Tne beautiful light given out 

 by these Molluscous animals soon subsided (being seen emitted from every part of 

 their bothes) ; but by moving them about, it could be reproduced for some length of 

 time after. As long as the luminosity of the ocean was visible (which continued most 

 part of the nightj a number of Pyrosoma Atlanticumt two species of Phyllosoma, an 

 animal apparently alHed to Septocephalus, as well as several Crustaccous animals, all 

 of which I had before considered as inter-tropical species, were caught and preserved. 

 At half-past ton p.m. the temperature of the atmosphere on deck was 52'=', and that 

 oi' the water 51^°. The luminosity of the water gradually decreased during the night, 

 and towards morning was no longer scon, nor on any subsequent night." 



In a paper which Mr Bennett read before the Zoological Society, 2oth June 1833, 

 these luminous animals ai-e more fully described. 



Specimens taken from the sea, and placed in a glass vessel containing sea-water, 

 ceased altogether to emit light, or emitted it but sparingly, while they remained at 

 rest. On the water being agitated, or when one from the masses of animals was 

 taken uito the hand, the whole became instantly illuminated by myriads of bright dots, 



much resembling in hue the points on the elytra of a diamond beetle (Curculio im» 

 perialis, Fah.) 



The Pyrosoma, thus enveloped throughout it^ whole extent in a flame of bright 

 phosphorescent light, gleaming with its peculiar hue, presented a most splendid spec- 

 tacle ; the hght shed by it was sufficient to render objects distinctly visible in every 

 part of an otherwise dark room. If long retained in the hand, or returned to a quies- 

 cent state in the water, the luminous spots gradually faded, and no light was visible 

 until the animal was again disturbed, when the illumination instantly returned with 

 all its vivid splendour. After death it emitted no light. 



The mass of Pyrosoma, of the usual cylindrical form and gelatinous substance, was 

 about four inches in length, and one-and-a-half in circumference. The tube, passing 

 along its middle, is described as being open at both ends; the orifice at the broader 

 extremity being much better defined in its circular form, larger, and more distinct 

 than that of the opposite end. The surface of the mass appeared to be studded with 

 numerous prominent, rigid, and pearly tubercles, intermingled with small specks of a 

 brown or red colour. In these latter the power of emitting hght appear chiefly to be 

 seated, these being frequently bright, while the remainder of the body exhibited only 

 its natural white, or yellowish-white hue — a hue which changed after death into a red 

 tinge. The brown specks, when removed from the body, did not emit light. 



The extensive field of bright luminous matter, from which these specimens were 

 taken, emitted so powerful a light as to illuminate the sails, and to permit a book of 

 small print to be read with facihty near the windows of the stern-cabms. Above this 

 luminous field numerous sea-fowl were hovering in search of their prey. The hght 

 appeared to be entirely owing to the Pyrosomata. 



The phosphorescence of the ocean often proceeds from other causes besides this 

 one ascertained by Mr Bennett. Frequently it arises from putrescent particles of ani- 

 mal matter, dissolved by the sea water. Sometimes it is occasioned by minute ani- 

 malcules, which possess the same remarkable property of shining in the dark with the 

 fire-fly of tropical climates (^Elater noctilueiis) , and the common glow-worm (Lampyris 

 nociiluca). But many observers have examined sea-water, and were imable to pfer- 

 ceive any animal matter in it. Professor Rennie states, that, being at Havre-de- 

 Grace, he could not discover the shghtest trace of animalcules, although the water 

 which he examined was so strongly luminous, that it shone upon the skin of some 

 night-bathers like scattered clouds of lambent flame, appearing more as a property of 

 the water itself than any thing extraneous difi'used through it. 



In all those cases, the phosphorescent bodies merely emit, during the night, the 

 solar rays which had been absorbed during the preceding day. The presence of salt 

 seems necessary to phosphorescence, as the water of ponds and lakes is never lumi- 

 nous. It may probably proceed from a similar cause with the luminous appearance 

 observed by chemists during the crystalhzation of some salts, as the hydro-fluate of 

 soda, and sulphate of potash. 



A recent writer has described five varieties of these luminous appearances. The 

 first shows itself in scattered sparkles in the spray of the sea, and iu the foam created 

 by the way of the ship when the water is agitated by the winds or currents; the se- 

 cond is a flash of pale hght, of momenta,ry duration, but often intense enough to illu- 

 minate the water to an extent of several feet; the third, of rare occurrence and pecu- 

 har to gulfs, bays, and shallows, in warm climates, is a diffused pale phosphorescence, 

 resembhng sometimes a sea of milk, or of some metal in a state of igneous hquefaction; 

 the fourth presents itself to the astonished voyager, under the appearance of thick bars 

 of metal, of about half a foot in length, ignited to whiteness, scattered over the surface 

 of the ocean, some rising up and continuing luminous as long as they remain in view, 

 while others decline and disappear ; and the fifth variety is iu distinct spots on the sur- 

 face, of great beauty and brilUancy. The light of the first variety is more brilhant 

 and condensed than that of any of the others, and very much resembles every way the 

 red gold and silver rain of the pyrotechnist. The first and the thu-d kind are pro- 

 duced by myriads of various minute Crustaceous animals, the smaller Medusce and 

 Mollusca, and perhaps some Annelid-es; the second appears to proceed from the ge- 

 latinous Medusa, of a larger size; the Pyrosomata are the cause of the fourth kind, 

 which may be often witnessed by vessels bound to India, or the eastward of the Cape 

 of Good Hope, occurring in the calm latitudes near the line. The Sapphirina indi- 

 cator, an insect somewhat resembhng in appearance the w^ood-louse ( Onisctis), and 

 about one-third of an inch in length, emits the last variety enumerated, which appears 

 to be hmited to the seas situate on the north and west of a line drawn frum the Cape 

 of Good Hope to the southern extremity of the island of Ceylon. 



Every page of Mr Bennett's excellent work is filled with interesting matter. There 

 ai*e some trifling inaccuracies, which we shall pass over in silence. We remark, how- 

 ever, that the author seems disposed to indulge in rather a satirical mode of expres- 

 sion towards the fair sex; and some remarks are made, which we think might have 

 been omitted without prejudice to the work. Thus, in describing the town of Sydney, 

 he observes — " Parrots ai-e perhaps, of all the feathered tribe, the most numerous in 

 the colony; and different species are lauded for speaking, whistUng, and other noisy 

 accomplishments. These birds are evidently gifted with the bump of talkaiivenens. 

 It was once asserted that ladies kept the birds to converse with when alone, which 

 served a double purpose — that of being to them both practice and amusement." We 

 also find a chapter headed " Female Curiosity;" and, on examination, it turns out to 

 be merely, that as the white men passed their dwellings, the ladies came forth to 

 view the strangers, "with the usual feminine curiosity." Yet, immediately after- 

 wards, we find that the nativts (men as well as women) seemed to regard them as 

 wonders. 



We hope to return, on another occasion, to these otherwise interesting pages; and, 

 in the meantime, we can recommend every student of Nature, to whom these books 

 are accessible, to pei 'ise them attentively. 



Edinburgh: Published for the pROpaiEi'ORS, at their Office, 16, Hanover Street. 

 Louden: Charles Tilt, Fleet Street. Dubhn: W, F. Wakeman, 9, D Olier 

 Street. Glasgow and the West of Scotland: John Smith and Sox, 70, St 

 Vincent Street. 



THE EDINBURGH TRINTIKG COMPANY. 



