substance is exposed to the sun's rays, are not due, as has long been supposed, to the agency of light, but are simply and purely a result of unequal heat, the crystals always forming upon the coldest side of the bottle. He has done the cause of science a service by correcting statements upon the subject which have been made in nearly all our leading chemical works.

Principal J. D. Forbes has published an elaborate paper in the “Transactions of the Royal Society of Edinburgh," "On the Conduction of Heat in Bars, and the Conducting Power of Wrought-Iron," and has observed that the order of arrangement of the "conductors of heat differs but little from their order of conduction for electricity," and thus confirms the results previously obtained by Wiedmann and Franz; also that "the diminished conducting power of iron, by increased temperature, harmonizes with similar facts in electricity."

M. Reitlanger has communicated a memoir to the Academy of Sciences at Vienna, "On the Sounds and Motion which take place within the Voltaic Arc." He employed Trevelyan's apparatus, driven by a voltaic current according to Mr. Page's process; and in some of the experiments the apparatus was placed in an exhausted receiver. He concludes that the sounds emitted by the above apparatus, as well as the motion of the revolving globes of Mr. Gore, are simply mechanical results of the electric discharge between the various movable metallic parts of the apparatus, where they are in imperfect contact with each other, and result especially from the tearing action.

Some interesting details respecting a discharge of lightning down a poplar tree are given in L'Institut. The lightning produced a groove like the furrow of a ploughshare, which did not proceed in a vertical line, but followed a spiral direction down the tree. It is interesting to notice this direction of action, as in another instance, at Birmingham, on the occasion of the Queen's visit to that place, lightning struck a pole fixed upon the Town Hall, and the direction taken by the electricity was also in that case in the form of a spiral down the pole.

ZOOLOGY.

M. du Chaillu and the Gorillas.-The long-vexed question of the authenticity of M. du Chaillu's travels in Equatorial Africa has received fresh light from Mr. W. Winwood Reade, who writing from Loanda, September 7, says :

"Having spent five active months in the gorilla country, I am in a position to state that M. du Chaillu has shot neither leopards, buffalos, nor gorillas; that the gorilla does not beat his breast like a drum; that the kulu-kamba does not utter the cry of Kooloo, or anything like it; that the young gorilla, in captivity, is not savage; and that while M. du Chaillu affects to have been a poor fever-stricken wretch at Camma (June 1, 1859), he was really residing, in robust health, at the Gaboon."

Mr. Reade admits that

"From the same source which afforded me proofs of his (Du Chaillu's) impostures, I learn that he is a good marksman; possessed of no common courage and endurance; that he has suffered many privations and misfortunes of which he has said nothing; that his character, as a trader, has been unjustly blemished; that his labours, as a naturalist, have been very remarkable; and that, during his residence in Africa, he won the affection of the natives and the esteem of those who most merit to be esteemedthe missionaries."

M. du Chaillu, not content with these concessions, in a letter to the Times, endeavours, from Mr. Reade's letter, to make it appear that the charges of misrepresentation still retained against him are groundless; and concludes by proposing that Dr. Gray and his friends shall deposit £2,000 on the one side, while he, on his part, will deposit £1,000; and, this being done, he will repair to the gorilla country, and if he succeeded in two years in bringing home eight perfect skins of gorillas, preserved with a preparation to be supplied by Dr. Gray, he would then claim the £2,000 in payment of his expenses; while, on the other hand, in case of failure, he would forfeit his £1,000.*

Habits of the Gorilla.-So much has been asserted of a marvellous character concerning these extraordinary animals, that we are glad to receive reliable information of a less romantic kind. Mr. Reade represents him as dwelling only in the densest parts of the forest, and feeding

* This proposed wager, on the part of M. du Chaillu, is treated as a joke by the Athenæum (December 6); a contributor to which journal says that an African trader would supply the five or six specimens in two years for £100. We have no desire to defend M. du Chaillu's illuminations, but we certainly think it would have been more satisfactory if Mr. Reade had given us the grounds on which he stated that M. du Chaillu had never shot gorillas, &c. To us, it seems very much as though Mr. Reade had felt bound to write something, and had done it.-ED.

VOL. II.-NO. VI.

X

exclusively on vegetable matter, so that one kind of grass is always a sure indication of his proximity. At noon and eve he approaches the village plantations in search of plantains, occasionally uttering a wild cry, but which in rage becomes a sharp bark. By day he moves along the ground on all-fours, sometimes ascending trees; and by night he selects a large tree as his sleeping-place. He is exceedingly wary and keen of scent. The female, when about to produce young, builds a nest of rude layers of dry sticks and small branches torn off from the trees by the hand. When wounded, or missed, as a rule they will charge on all-fours; but the natives, being as nimble as apes, often escape. In the case of a man who had his hand crippled by the bite of a gorilla, the animal seized the wrist with his hind foot, and dragged the hand into his mouth as he would have done a bunch of plantains. Only traditional accounts exist of the gorilla having killed a man; and it is less feared than the leopard.

The Gorilla in Liverpool.-So celebrated has this ape become, that the acquisition of a good specimen is an important event to a museum. The Free Public Museum of Liverpool has just acquired a specimen, superior, perhaps, to any in this country in size and excellence of preservation. An account of the arrival of this skin (which was presented to the museum by Mr. Duckworth) will be found in vol. i. p. 537. The same museum is particularly rich in illustrations of this animal, and possesses the largest gorilla-skeleton in Europe.

It has been very currently reported that a young living gorilla has been exhibited at Liverpool. This, however, is an error; the animal in question being only a chimpanzee. The only living gorilla which was ever imported into this country was in the possession of Mrs. Wombwell in 1855–56, and was examined by Mr. Moore, the curator of the Liverpool Museum. It was very docile and active, and is now in the possession of Mr. Waterton, forming one of the remarkable features of that gentleman's museum at Walton Hall, where it has been seen and examined by the writer.

The Unicorn.—The controversy concerning the existence of this animal still continues. The distinguished naturalist, Rüppell, received accounts many years back which inclined him to believe that some such animal existed in the deserts lying south of Kordofan. The zoological objection to the possibility of the existence of an animal with a single (true) horn on the middle of the forehead, is, that no such horn can grow upon a suture of the skull. It is believed, however, by some authorities that the male giraffe possesses a third horn, growing from the very centre of the frontal suture.

The New British Snake.-The newly-discovered Coronella has again been taken in the New Forest, whence a female specimen was obtained and taken to Mr. F. Buckland. While in his possession it produced six young, two of which were drowned in the water placed in the cage; the remainder appeared to be well cared for by the parent snake. It is thus proved that this reptile is, like the adder, viviparous.

The King Crab (Limulus polyphemus) found at Dover.-This remarkable animal, the nearest living representative of the ancient trilobite, has lately been imported in some numbers into Liverpool, alive; and also into London. One was taken to the Jardin des Plantes at Paris, for pre

sentation to one of the professors; but, for some reason, it was not presented, and, returning to England, it was thrown overboard in the Straits of Dover. Soon afterwards a person presented himself at the British Museum, and offered a living specimen for sale, asking for it £5, and averring that it had been taken at Dover. Could it be that it was the same individual that was thrown overboard in the Straits? At all events, it should be borne in mind that if found in future it is a naturalized, and not an indigenous, animal on our coast.

Discovery of Aquatic Hymenopterous Insects.-Mr. Lubbock, F.R.S., exhibited, at the Entomological Society, two species of aquatic hymenopterous insects, one of which swims with its wings. They were found in a basin of water obtained from a pond. While examining the Entomostraca swimming about in it, he was struck with astonishment at observing a small, veritable, clear-winged insect swimming with an easy, graceful, jerking movement, by means of its wings. Although some of the hymenoptera had been observed to descend temporarily into the water, this was the first which had been met with which was truly aquatic. He proposed to call it Polynema natans, and remarked that, in a paleontological point of view, it was worthy of notice that, had it been found fossil, there would have been nothing to indicate that it was not a terrestrial or aërial animal.

Cultivation of Oysters.-M. Coste has communicated to the Academy of Sciences an account of the progress of his oyster-beds on the west coast of France. That waves and currents carry the ova of oysters is a wellknown fact, since the walls of newly-erected sluices are often covered with them; but in the island of Ré, where the inhabitants have for some years been engaged in cleansing the muddy sediment from their coast, the oysters are now permanently established. Seventy-two millions of oysters, from one to four years old, is the lowest average registered per annum by the local administration, representing a value of about two millions of francs (£80,000).

Iron-banks built by Animalcules.-M. de Watteville announces, in the Journal de l'Instruction Publique, that in the lakes of Sweden there are vast layers or banks of iron, exclusively built up by animalcules. This iron is called lake ore, and distinguished, according to its form, into gunpowder, pearl, money, or cake ore. In winter, the Swedish peasant, who has but little to do at that season, makes holes in the ice of a lake, and probes for an iron-bank; then, letting down a sieve, the loose ore is shovelled into it with a ladle, mixed, of course, with sand, which is got rid of by washing it in a cradle. One man may obtain a ton of iron ore per diem by this process.

Fleet of Portuguese Men-of-War (Physalia pelagica) off the Isle of Wight. This beautiful Medusa, which, as its name indicates, is oceanic, has lately made its appearance in great numbers off the Isle of Wight after a storm. Many of them were alive, and lived two days in a basin of salt-water. They are very rarely taken on British shores.

The Royal College of Surgeons of England has recently purchased for its museum a collection of specimens of animals from Professor Hyrtl of Vienna. The chief object of interest was the skeleton and stuffed skin of

a little animal, the Chlamydophorus Truncatus. This creature is about the size of a rat, and possesses certain anatomical peculiarities, concerning which Professor Hyrtl published a monograph in 1855. On this account, and also for its extreme rarity, the sum of £40 was given for that object alone. There are but two specimens known of one is in the Anatomical Museum of the London Zoological Gardens; the other is the one mentioned above. Neither are there likely to be any more seen; for the only place in which the Chlamydophorus has been found was in the town of Mendoza, in the high lands of Chili, and which was totally buried, with its 14,000 inhabitants, by an earthquake in the Andes, in 1861.