"1. Coloured shadows may be distinguished into objective and subjective.

"2. The former owe their colouring to the light which arrives at them either directly or by reflection; they are not therefore total shadows, but are rather, to use the scientific term, penumbra.

"3. The shadows whose colouring is subjective, are the effect of a particular disposition of our organ, which, when it is fatigued by the impression of a single colour, no longer perceives that ray in a fasciculus of white light; so that the complementary ray predominates and communicates its tint to the shadow projected in the primitive light.

"4. So far as we have been able to observe, the eye follows in this process the scale of Newton. If the corresponding colours are not always exactly complementary, it must be attributed to the difficulty of obtaining artificial tints so pure as those of the solar spectrum.

"5. There follows from this, that the colouring of shadows is impossible, if there be no other light than that by the interception of which the shadow is formed. The presence of a light coming from another part, for example, from the sky, or the clouds, is an indispensable condition to the formation of coloured shadows.

"6. Lastly, the shadow is not necessary to make the complementary colours appear. A small quantity of white light, put in prominent contrast with a large mass of coloured light, assumes, in certain circumstances which we cannot well determine, the complementary tint corresponding to the colour of this latter light."

Mr Trechsel's explanation appears to us satisfactory; it introduces, it is true, two causes for a phenomenon which has usually been considered as one; but this is not the first case where a careful analysis has obliged us to admit several agents in an effect single in appearance. Without doubt, in the number of the very varied experiments which may be made on the subject of coloured shadows, there will still present themselves many details which will not be immediately explained; but it is probable that their origin will be found in the peculiar circumstances of

these experiments, and in the state of the bodies employed by the philosopher in his observations.

Bibliotheque Universelle, May 1826.

Notice regarding the Little Andaman Island, Bay of Bengal. Communicated by Cornet J. E. ALEXANDER, H. M. 13th Light Dragoons. With a Plate.

On the 12th November 1825, the Honourable Company's transport, Earl Kellie, having on board 4 companies of H. M. 45th regiment, and 100 Madras pioneers, destined for foreign service in the Birman Empire, steering a S.E. course, hove in sight of the Little Andaman Island, in latitude 10° 45′ N., and longitude 92° 12′ E., bearing from E. to E.S E., and distant 4 leagues. At 10 A. M. bore up, and stood in for the land to get a supply of water, our stock of which was almost exhausted, from the unusual length of the voyage, occasioned by the baffling winds we experienced in the middle of the Bay. At 11 saw a brig, hull down, bearing N. W., steering to the S. E. At 12 sounded on a coral reef 8, 9, 10, 12, and 16 fathoms, patches, the bottom seen plainly under the ship, with numerous sharks following the vessel, one of which we succeeded in killing. Observed a murana ophis or sea-serpent; length about 3 feet; back brownish, belly white, tail rounded, a row of black spots along the sides, and without the caudal fin. A monstrous fish likewise made its appearance near the vessel, seemingly of the genus Raia or ray; its length about 20 or 25 feet, very broad, and colour of back reddish. A very heavy swell on the bank; steering from N.N.E. to N.W. to haul off it, ran a distance of 4 knots, when the water deepened to 20 fathoms. When on the coral shoal, in 8 fathoms water, the extremes of the island from E. W. to N.N.E., and a small bay in the centre of the island ;—at 11 P. M. saw a light on shore; brought up the N.W. point, and anchored in 81 fathoms, at 24 miles from shore.

off

13th November.-At daylight proceeded in one of the cutters along with the chief mate in search of water. On approaching the shore, observed a woman and child on the beach, who, upon perceiving the boat, ran into the jungle; they appeared to

be employed in collecting shell-fish. Found a small sandy bay (which I took the liberty of naming after the ship), with coral reefs running out from both extremes, over which a tremendous surf was breaking; inside the water was quite smooth. Anchored the boat a few fathoms' length from shore; and, leaving a couple of hands in her, landed with the remainder of the Lascar crew, six in number, who were armed with muskets.

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We found the island (which in length is 28 miles, by 15 in breadth), to be of coral formation, entirely flat, and covered with lofty and thick jungle to within a few yards of the water's edge. Proceeded along-shore towards the N. W. point in search of two rills of water mentioned by Horsburgh in his " Directory." At an angle of the jungle came suddenly upon a party of the natives lying on their bellies behind the bushes, armed with spears, arrows, and long bows, which they bent at us in a threatening manner. The moment the Lascars saw them they fell back in great consternation, levelling their muskets; and it was with great difficulty we could prevent them from firing; only the tyndal or coxswain (a Malay) stood by us. We went within a few paces of the natives, and made signs of drinking. The tyndal salaamed to them according to the different oriental modes of salutation. He spoke to them in Malays and other languages. They returned no answer, but continued crouching in their menacing attitude; and to whichever side we turned, they pointed their weapons towards us. I held out my handkerchief towards them, but they would not come from behind the bushes to take it. I placed it upon the ground, and we retired, in order to allow them to pick it up. Still they moved not. I counted 16 strong and able bodied men opposite to us, many of them very lusty; and further on another party six or eight in number. Those in front of us were lying in two ranks, with two or three women in the rear; the whole of them completely naked, with the exception of a stout man, about six feet in height, who was standing up along with the women. · He wore on his head a red cloth, with white spots, and probably was their chief. They were the most ferocious and wild looking beings that I ever saw; their hair was frizzled, noses flat, and small red eyes; those parts of their skin which were not besmeared with mud (probably to shield them from the attacks of insects) were a

sooty black; their hideous faces seemed to be painted with red ochre. I may here remark, that the inhabitants of the Andaman Islands, decidedly a negro race, and differing widely from those of the neighbouring continent, are supposed to be the descendants of the survivors from the wreck of an Arab slave ship, said to have been lost here some centuries ago. The Chinese, who occasionally resort to these islands to collect the edible nests of the Hirundo esculenta, affirm that the natives are anthropophagi. One thing, however, is certain, that several boats' crews have fallen into their hands, and have never since been heard of.

At the above stage of the rencontre, the other cutter, with two or three of the officers on board, neared the beach, and seeing what we were about, they called to us to retire a short distance, and allow the tyndal to go up and speak to the savages, for perhaps they were afraid of Europeans. We fell back to the water's edge, and having caused the tyndal to strip to shew them that he was unarmed, he went up to within a few paces of them, and offered them a couple of handkerchiefs, making at the same time signs of drinking; but upon his attempting to approach nearer, they drew their bows and threatened him. Seeing this we called him off; and not knowing how to act in this emergency, without advice from the ship, as we had been requested not to use any violence, both cutters returned to the vessel; and upon reporting what we had seen relative to the hostile disposition evinced by the natives, a subaltern's party of the 45th, with a couple of buglers, and pioneers to fill the water-casks, were ordered to accompany us, in order that we might force our way to the water if necessary. We landed at the same spot we had formerly done, and not seeing any thing of the natives, we advanced along the beach towards the southward; and, upon turning a point, saw flocks of sand-larks, curlews, &c. Further on we discovered a hut on the edge of the jungle: we went to it, and found it to be about 20 feet in height, of a conical shape, thatched to within a foot and a-half of the ground with rattan leaves, with just room to crawl in underneath. The floor inside was strewed with leaves, and there were several cots or sleeping places in different parts; they consisted of four sticks driven into the ground, on which was fixed a bamboo grating. Ranged

in a row round the walls were the smoked skulls of a diminutive hog; the canine teeth shorter than in the other species of sus in eastern countries, the jaws fastened together by strips of rattan, (Plate I. fig. 1.) From the roof a piece of red and white chequered cloth was suspended, seemingly of Madras manufacture. In conical baskets pieces of jack-fruit were found, and a nut resembling a chesnut, besides several roots. In a corner I found several large mangroves. At a fire the following shells were roasting: The green Murex tribulus, Trochus telescopium, Cypræa caurica, and several varieties of mussel. The drinking cups seemed to be the nautilus. The weapons were a bow from 6 to 7 feet in length, which is pulled with the feet, and a hand-bow of 4 feet; the strings are made of the dark red fibres of a tree. The arrows are 3 and 4 feet in length, the upper part of a very hard white wood, inserted in a stock of cane. The soldiers shot several of them at a tree; they penetrated a couple of inches into the solid timber, and it required the joint strength of two men to pull them out, and even then the points were uninjured. Several arrows were found with two, three, and four prongs. No canoes or rafts were seen, and no idols of any description. The hand-nets were formed of the black filaments of a tree. In one of the baskets, carefully wrapped up in a cloth, were the head of a harpoon with two barbs, a Malay chopping knife, and several spike-nails and ring-bolts; these last were probably from the American ship Dover, Captain Duffin, which was wrecked here several years ago.

Naturally concluding that there was water near the hut, we penetrated into the jungle, consisting of Dammer trees, red-wood, the Alexandrian laurel, aloes, rattans, and a very lofty and straight tree, about 15 feet in girth, which, if not too heavy, would answer admirably for masts. Having advanced about 30 or 40 yards from the beach, came to a pool of good water; but, from its being at an inconvenient distance from the vessel, we retraced our steps, and, on coming opposite the boats, discovered a party of 50 or 60 natives waiting our approach in ambush. We advanced to them, in order to get them to point out a more convenient watering place. So little intention had we of molesting or injuring them, that we had brought with us several looking-glasses, cloth, and baubles to give them. How