at least when in a state of captivity." Upon this Mr. Vigors observes it is observed to perch not across a branch, but on its longitudina. that such can be at best but an accidental use to which the serration direction. These birds affect the neighbourhood of oaks, where in can be applied. There are many other groups of birds, he adds, pos- May they find the Melolontha vulgaris, and at Midsummer the M. solsessing the same character, to which the same application of it can stitialis. White graphically describes the evolutions of one round his never be assigned-for instance, the greater part of the genus Pele-great spreading oak,' where it was hawking after a brood of some canus of Linnæus. Many of these birds, whose feet, Mr Vigors ob- particular Phalana belonging to that tree. On this occasion he says serves, are naturally ill adapted by their webbed structure for laying it exhibited a command of wing superior to the swallow itself. The hold of any object, are yet found to incubate among trees, where the same author states that when a person approaches the haunts of this serrated claw may give them a further power of prehension; they are species in an evening they continue flying round the head of the also, he remarks, asserted to seize their prey occasionally with the obtruder; and by striking their wings together above their backs, in foot; in which acts the structure of the nail, as in the case cited by the manner that the pigeons called Smiters are known to do, make White respecting the Caprimulgus, may be peculiarly useful. "The a short snap; perhaps at that time, he adds, they are jealous of their family of the Ardeida among the wading birds equally exhibit," says young, and their noise and gestures are intended by way of menace. Mr. Vigors, in conclusion, "an analogous construction in the middle The eggs, two in number, oblong, white or dusky, and streaked somenail. Here again this character seems adapted to their mode of life what like the plumage of the bird, are equal in size at each end, and in enabling them to hold their prey more firmly in those slimy and are laid on the bare ground, generally among fern, heath, or long muddy situations where it might otherwise elude them; while, at the grass, sometimes in furze-brakes or woods, but always near the latter. same time, it may assist their feet (which, like those of the Pelecanida, Montagu describes the noise made by the male during incubation are naturally ill suited for grasping) in their hold among the trees, when perched, and with his head downwards, as not unlike that where, like some also of the latter family, they build their nests." of a spinning-wheel, and notices its uttering a sharp squeak as Mr. Dillon is of opinion that the chief use of the serrated claw it flies. is simply to comb out or dress the vibrissæ which surround the gape. Mr. Swainson opposes this view, observing that there is an American group of this family which have no bristles round the bill, and yet have the serrated claws; and another group in Australia which have bristles round the bill, and yet with the claw smooth and simple. He also observes that the Heron tribe have the gape smooth, but the claw serrated. Mr. Rennie remarks that the passage in Wilson "appears to settle the question;" but he gives no satisfactory reason why. The other European species, Caprimulgus ruficollis, which is very rare, has been shot in the oak-woods some miles distant from Algeziras, and also in the valley of the Rio del Mel, near that city. The Spanish name for it is Samala. Mr. Gould has no doubt that its natural habitat is Northern Africa. Prince Bonaparte notes it as occurring in south-western Europe during the summer. Mr. Gould has established a new genus for some of the American Caprimulgi, under the name of Antrostomus. [WHIP-POOR-WILL-] Psalurus (Sw.).-Gape strongly bristled. Tail excessively long, and very deeply forked. P. macropterus. A bright ruddy demi-collar ornaments the back part of the neck, and the two external tail-feathers in the male are much longer than the others. The tail of the female is much shorter. It is a native of Paraguay and Brazil. Chordeiles (Sw.).-Gape perfectly smooth. Wings very long, equal to the tail, which is slightly forked. C. Americanus. Ground of plumage above, sides of the head, and front of the neck, dark liver-brown, glossed with greenish. Head, neck, and upper rows of lesser wing-coverts, spotted with yellowishbrown; back, scapulars, and tertiaries, mottled with brownish-white and a little wood-brown, the pale colour forming speckled bars on the tail and its coverts; intermediate wing-coverts more thickly mottled with a purer white: greater coverts spotted with brown on the margin; band on middle of quills, beginning on the inner web of the first and ending with the fifth, and a broad arrow-shaped mark on the throat, pure white. A white dotted superciliary band reaches to the nape. Lateral tail-feathers banded with white. Plumage below and inner wing-coverts barred alternately with brownish-white and liverbrown. Bill blackish. Legs pale. Tail forked. Middle toe, which is longest, with a serrated claw. This is the Caprimulgus Americanus of Wilson, and the C. Virginianus of Prince Bonaparte, who notices the bird in his 'Geographical and Comparative List,' as Chordeiles Virginianus (Bonap.), and Caprimulgus Popetue (Vieill.). It is the Peesquaw of the Cree Indians. Sir John Richardson says that few birds are better known in the Fur Countries than this, which ranges in summer even to the most remote arctic islands. Colonel Sabine notices it, in the appendix to Captain (now Sir Edward) Parry's First Voyage,' as the Musquito Hawk, and states that a female was found on Melville Island, lying dead on the ground about a quarter of a mile from the sea. He adds, that these birds are known to breed and inhabit as far north as Hudson's Bay; but as they live principally in woods, and feed on musquitoes and other winged insects, which are very rare in the North Georgian Islands, it is more than probable that the individual found dead was an accidental visitor, and had perished for want of food. It was extremely thin, but the plumage was in good preservation. Fabricius does not mention it, he observes in conclusion, as known in Greenland. Sir John Richardson states that its very peculiar noise is most frequently heard in the evening, and often seems to be made close to the listener, though the bird that produces it is so high in the air as to be nearly imperceptible. He describes this sound as resembling that produced by the vibration of a tense thick cord in a violent gust of wind, and says that the Pisk (the common name for the bird) considerably resembles some of the Falconida in its evolutions in the air. It often remains stationary, fluttering its wings rapidly, and then suddenly shoots off a long way by a gliding motion: at that moment the loud vibratory noise is heard. "It also traverses the air backwards, and forwards, quartering the sky as regularly as the Hen Harrier surveys a piece of ground. The female deposits her eggs on the ground without making any nest, generally selecting the border of a cultivated field or an open glade in the forest, and during incubation sits so close that she may be almost trodden down. When any person approaches her the male sallies from the adjacent thicket and stoops at the intruder, passing within a foot or two of his head, then rising again and wheeling round to repeat the same manoeuvre. In the meanwhile his mate flutters from the nest along the ground as if disabled, and hides herself at a short distance among the gray grass, from which she can hardly be distinguished. The Pisk makes its first appearance at Great Bear Lake generally about the last day of May, and was observed hatching on the Saskatchewan on the 8th of June. Its eggs are narrower than those of Caprimulgus vociferus, but of the same colours, rather differently distributed; they measure nearly 14 lines in length." ("Fauna Boreali-Americana.') is entirely black, without any rufous, their tips only being freckled with gray; but they are crossed in the middle by a snowy-white broad band beginning in the inner web of the first and terminating on the outer web of the sixth quill: the remaining quills are varied with black and rufous and tipped with white. The tail is variegated in the usual manner, the middle pair of feathers having about twenty very slender transverse bars, but much undulated, while the outer margin of the exterior feather, and the tips of that and of the next are pure white. No gray in the plumage. Total length, including tail, 13 inches. (Sw.) It is a native of Africa, and is common in Senegal. Pisk (Chordeiles Americanus). Upper figure, male; lower figure, female, with an egg. Sir John Richardson states the extreme northern range of this bird as 68° N. lat. (east of the Rocky Mountains, migratory), and he notices it as observed in the summer, when it is common, on the Saskatchewan, lat. 53° to 54° N., and from 600 to 1000 miles distant from the seacoast; as very common in the vicinity of Philadelphia, lat. 40° N. (Bonaparte), but as not having its winter-quarters in the United States. It also appears in Sir John's list of species which summer or breed in the Fur Countries and in Pennsylvania, but winter farther to the In Prince Bonaparte's Geographical and Comparative List,' the southern and central parts of North America are recorded as the localities of the species. southward. Scotornis (Sw.).-General structure of Caprimulgus; but the outer toe is shorter than the inner. Sub-genera, Scotornis.-Rictus strongly bristled. Tail lengthened, graduated, or rounded. (Sw.) African Long-Tailed Night-Jar (Scotornis climaturus). (Caprimulgus Macrodipteryx (Sw.).-Rictus strongly bristled; wings long, equal to the tail, and with a lengthened reniform feather in each. Tail even. M. Africanus, Pennant-Winged Night-Jar, or Long-Shafted GoatSucker. It has wings, for the small size of the bird, very long, rather exceeding, or at least equalling, the tip of the tail, which is quite even and consists of ten feathers. Of the first three quills, which are much the longest, the first is shorter than the third, which is slightly succeeded by the second. The long-shafted feathers are inserted immediately between the primary and secondary quills. The bristles of the mouth are strong and equal to the length of the bill, which is weak. The middle toe is lengthened, and the lateral toes are equal. Colour of the plumage mixed, as in others of the family. Upon each web of each of the primary quills is a row of nine rufous and nine black spots: the rufous bars become very small towards the tips, where the black predominates. The lesser quills are black, with four rufous bands, the tips black. The middle tail-feathers are gray, speckled with black points, and crossed by six black bars, all of which are irregular, excepting the last, which, as on all the other feathers, is regular, well defined, and placed just behind the tips; the outer web of the exterior feather is fulvous white, with about ten black spots, at equal distances from each other. Some of the scapulars have a broad cream-coloured stripe, which forms a connected series when the feathers lay over each other, but those which are conspicuous on the supposed female can scarcely be discerned in the male; this latter however has a few obscure white mottles on the chin, throat, and round the ears. Total length about 8 inches. S. climaturus, African Long-Tailed Night-Jar. Its size is rather smaller than that of Macrodipteryx, although, from the development of its tail, it is much longer. The bristles considerably exceed the length of the bill; the third quill is longest; the first is rather shorter than the fourth, while the fifth is ths of an inch shorter than the fourth. The tail is very long, measuring from the base 9 inches, of which 34 inches are occasioned by the two middle tail-feathers exceeding the others; the outer lateral toe is shorter than the inner. The ground colour of the plumage is light ferruginous-brown varied with dark freckles. The chin and rictal stripe white; the lesser wing-coverts have at their tips a broad band of white, and the greater have a terminal spot of cream-colour, much smaller than the former. The ground colour of the five primary quills Mr. Swainson, from whose 'Birds of Western Africa,' the above description is taken, observes that the female is entirely destitute of the long-shafted or supplementary feathers. "Now this," says Mr. Swainson, "is a very important fact, for it goes far to prove that they are not essential to the economy of the species; for if otherwise, both sexes would possess them, unless it be contended, a supposition highly improbable, that the male feeds in one manner and the female in another. In the absence of all information upon this point, we are led to conclude that they are more ornamental than useful, given to the male sex as attractive decorations to the female, in a similar manner as the flowing feathers of the Paradise Bird are known to distinguish the male sex. Whether or no these ornamental plumes are lost after the season of incubation is a subject for future inquiry; but they are certainly of very unequal lengths in different individuals. We have seen them in one bird only 7 inches long, while in that now before us they measure in extreme length 17 inches; the webs occupy exactly six, while all the rest of the shaft is naked, the rudimentary Pennant-Winged Night-Jar, or Long-Shafted Goat-Sucker (Macrodipteryx Africanus). Male. hairs on each side merely indicating the position of the lamina, had they been developed. We cannot subscribe to an opinion we have heard expressed, that these latter have been rubbed or worn off. Proïthera diurna. Another specimen, which we suppose is the female, is perfect in all its plumage, but has no indication, as already observed, of these feathers. In their texture they are remarkably flexible, moving about with the least breath of wind. The inner web is so broad, that the lamina in the middle measure 24 inches; the outer web, on the contrary, is very narrow, and the longest lamina are hardly half an inch." This is the Caprimulgus Macrodipterus of Afzelius, and the Caprimulgus longipennis of Shaw. It is a native of Sierra Leone, Africa. Proithera (Sw.).-Rictus almost smooth; wings very long, equal to the tail, which is short and even; tarsus very naked. P. diurna (Caprimulgus diurnus, Wied., Nacunda, Temm.). The plumage of the female is above a mixture of gray-brown, yellowishred, and brownish-black, marked with great spots of blackishbrown, with wide borders of yellowish-red; chin pale-yellow, striped with gray-brown; tail marbled with brownish-black and brightyellow, with nine or ten transverse bands speckled with brownishblack. Plumage beneath white lineated with gray-brown; middle of the belly white, spotless. Length rather more than 10 inches. It is a native of Brazil and Paraguay. GOAT'S THORN. [ASTRAGALUS.] GOAT-WEED. [EGOPODIUM.] GO'BIO, a genus of Fishes belonging to the section Malacopterygii Abdominales and family Cyprinidae. The species of this genus differ chiefly from the true Carps in having the anal and dorsal fins short and destitute of bony rays. G. fluviatilis (Ray), the Common Gudgeon, affords the best example of this genus. The Gudgeon is a British fish, and is found in many streams that in their course flow over gravelly soils. The Thames, Mersey, Colne, Kennet, and Avon, produce fine Gudgeons. They swim together in shoals, feeding on worms, aquatic insects, and their larvae, small molluscous animals, ova, and fry. They afford ample amusement to those sportsmen who are satisfied with numbers rather than weight. The Gudgeon rarely exceeds 8 inches in length. It spawns in May, and the young are about an inch long in August. GO'BIUS, a genus of Acanthopterygious Osseous Fishes belonging to the family Gobioida. All the species have two dorsal fins, scaly bodies, and a disc beneath the throat formed by the united ventral fins. By means of this disc they have the power of attaching themselves to rocks. Several species of Goby are met with on the British coast. The largest is the Gobius niger of Linnæus, which attains the length of 6 inches, and ranges from Cornwall to the Orkneys. Mr. Couch has inquired into the habits of the Black Goby, and finds that when it has seized its prey it carries it off alive in its mouth to its resting-place, which is among rocks. The other British Gobies, G. bipunctatus, G. minutus, G. gracilis, and G. unipunctatus, are mostly inhabitants of sandy ground. On the shores of the Mediterranean Gobies abound, and are also found in deep water, even to a depth of 50 fathoms. The deep-water species are distinct from those frequenting the coast-line. The species of Gobius are very tenacious of life, and are capable, like their neighbours, the Blennies, of living some time out of water. The most remarkable fact connected with the history of these fishes is their nidification. That the Goby built a nest was known to the ancient Greeks. This nest they construct in spring, of seaweeds, &e., and in it the female deposits her eggs, whilst the male watches over them until they are hatched. The nest of the Goby is very well built, and has of late been observed on our own coasts. True Gobies occur in the seas of the southern hemispheres as well as in those of the northern. GOBY. [GOBIUS.] GODWIT. [SCOLOPACIDE.] GOLD, one of the precious metals. It differs remarkably from other metals, with a very few exceptions, in the fact that it is found in nature in its metallic state. It is occasionally found mineralised by tellurium. Native gold is Monometric, and occurs in cubes without cleavage, also in grains, thin laminæ, and masses, sometimes filiform or reticulated. The colour varies in shade, sometimes being a bright yellow, at others almost silvery white, from the quantity of silver with which it is mixed. It is very ductile and malleable. Hardness 25 to 3. Specific gravity 12 to 20, varying according to the metals alloyed with the gold. Native gold usually contains silver, and in very various proportions. The finest native gold from Russia yielded-gold 98.96, silver 0.16, copper 0-35, iron 0.05; specific gravity 19-099. A gold from Marmato afforded only 73.45 per cent. of gold, with 26-48 per cent. of silver: specific gravity 12.666. This last is in the proportion of 3 of gold to 1 of silver. The following proportions have also been observed:-3 to 1, 5 to 1, 6 to 1, 8 to 1; and this is the most common; 12 to 1 also is of frequent Occurrence. Copper is often found in alloy with gold, and also Palladium and Rhodium. A Rhodium Gold from Mexico gave the specific gravity 15.5 to 16.8, and contained 34 to 43 per cent. of rhodium. Iron and copper pyrites are often mistaken for gold by those inexperienced in ores. Gold is at once distinguished by being easily cut in slices and flattening under a hammer. The pyrites when pounded are reduced to powder: iron pyrites is too hard to yield at all to a knife, and copper pyrites affords a dull greenish powder. Moreover the pyrites give off sulphur when strongly heated, while gold melts without any such odour. Native Gold is to a large extent obtained from alluvial washings. It is also found disseminated through certain rocks, especially quartz and talcose rocks, and it is often contained in pyrites, constituting the auriferous pyrites; the detritus affording gold-dust has proceeded from some gold-bearing rocks. Gold is widely distributed over the globe. It occurs in Brazil (where formerly a great part of that used was obtained), along the chain of mountains which runs nearly parallel with the coast, especially near Villa Rica, and in the province of Minas Geraes; in New Granada, at Antioquia, Choco, and Grion; in Chili; sparingly in Peru and Mexico; in the southern of the United States. In Europe it is most abundant, in Hungary, at Königsberg, Schemnitz, and Felsobanya, and in Transylvania, at Kapnik, Vorospatak, and Offenbanya; it occurs also in the sands of the Rhine, the Reuss, and the Aar; on the southern slope of the Pennine Alps, from the Simplon and Monte Rosa to the valley of Aosta; in Piedmont; in Spain, formerly worked in Asturias; in the county of Wicklow in Ireland; and in Sweden at Edelfors. In the Ural Mountains there are valuable mines, also in the Cailles Mountains in Little Tibet. There are mines in Africa at Kordofan, between Dar-fur and Abyssinia; also south of Sahara, in the western part of Africa from Senegal to Cape Palmas; also along the coast opposite Madagascar, between 22° and 23° S. lat., supposed to have been the Ophir of the time of Solomon. Other regions in which gold is found are China, Japan, Formosa, Ceylon, Java, Sumatra, and the Philippines. Until lately nearly all the gold of commerce came from Asiatic Russia and Mexico, but recent discoveries of gold in California and Australia have opened new and vast sources of supply. From 1600 to 1700 the entire supply of gold for Europe was obtained from America, whose mines are estimated in the one hundred years to have produced 337,500,000l. worth of the precious metal. During the 18th century the supply of gold and silver was still mainly derived from the Americas, the great mine of Valenciana, producing 125,000l. sterling per annum for 40 years, and the district of Zaccatecas adding largely to the amount, although these were rapidly failing towards the end of the century. A great increase of gold was produced from the mines of Russia, which are still very productive; they are principally alluvial washings, and these washings seldom yield more than 65 grains of gold for 4000 lbs. of soil, never more than 120 grains. The alluvium is generally most productive, where the loose material is most ferruginous. The mines of Ekaterinburg are in the parent rock-a quartz constituting veins in a half-decomposed granite called Beresite, which is connected with talcose and chloritic schists. The shafts are sunk vertically in the beresite, seldom below 25 feet, and thence lateral galleries are run to the veins. These mines afforded between the years 1725 and 1841 679 poods of gold, or about 30,000 lbs. troy. The whole of the Russian mines yielded in 1842, 970 poods of gold, or 42,000 lbs. troy, half of which was from Siberia, east of the Urals. In 1843 the yield was nearly 60,000 lbs. troy; in 1845, 62,000 lbs. troy; and in 1846, 75,353 lbs. In the five following years to 1851 nearly 296,932 lbs. troy weight of gold have been raised in Russia. At the Transylvania mines the gold is obtained by mining, and these mines have been worked since the time of the Romans. The annual yield of Europe exclusive of Russia is not above 250,000l. The sands of the Rhône, Rhine, and Danube contain gold in small quantities. The sands of the richest quality contain only about 56 parts of gold in 100,000,000. Sands containing less than half this proportion are worked. Africa yields annually at least 4500 lbs. troy, and Southern Africa 1250 lbs. The mines of the United States have lately produced about 1,000,000 dollars a year. In South America the gold region of California extends along the valley of the Sacramento and the valley of San Joaquin, immediately south. The gold occurs in flattened grains, or scales, and occasionally in lumps of large size. The yield is enormous. The amount received at the mint in the United States in 1851 was at the rate of 32,000,000 dollars a year. The aggregate production of gold in South America does not appear to have increased within the last five years. The rate of produce in the Australian mines is as follows:The Sydney district produced from 29th May 1851 to 31st October 1851, 67,152 oz. gold, value 214,8867., or to November 1851, 79,340 oz. gold, value at 257,855l. 78., and to December 31, 142,975 oz. gold, value 464,6687. 15s. In the Victoria district to the end of December 1851, Ballarat produced 25,108 oz., value 75,3241.; Mount Alexander, 30,007 oz., value 96,0217. In December there was shipped from Victoria 145,116 oz., on the 8th January, 75,188 oz. Only about twofifths of the gold realised is sent by the Government escort, hence there is much difficulty in arriving at the actual amount. But the imports to this country may be safely relied on as representing the maximum produce of our colonial gold-fields, and the auriferous districts of America. From November 1850 to June 1851 the Bank of England issued 9,500,000 sovereigns, being at the rate of 18,000,000 a year, and so great is the increasing demand for gold coins, that the rate of production can scarcely keep pace with it. of which not one-tenth can be recovered. For gilding metals by the electrotype and the water-gilding processes not less than 10,000 oz. of gold are required annually. One establishment in the Potteries employs 3500%. worth of gold per annum, and nearly 2000l. worth is used by another. The consumption of gold in the Potteries of Staffordshire for gilding porcelain and making crimson and rose-colour varies from 7000 to 10,000 oz. per annum. The Indus and the Euphrates were the earliest spots whence man obtained the precious metal gold-Nubia and Ethiopia on the south, and Siberia on the north next opened out their auriferous treasure to gratify human necessity and to indulge human luxury. Europe then began to unfold her golden stores, and Illyria and the Pyrenees, together with the land of the Hungarians and many parts of Germany to the Rhine, were sought successfully for gold. Our islands yielded something to the store, and then the New World of the Americans opened by Columbus a source from which the Old World was to supply its golden waste. On and on still westward rolled the golden ball, until at length it rested in California; Europe and Asia rush equally to that new El Dorado, and the man of China is found at the side of the English gold streamer. Then, as if to double the girdle, the islands of the Pacific and our own Australia open their exceeding stores. (Hunt.) Australia is undoubtedly the most important gold-bearing district in relation to Great Britain. Her shores are now being crowded with emigrants from the mother country seeking the precious metal, and in proportion to her population she is now undoubtedly, in this point of view, the richest country of the world. For the purpose of guiding those who are seeking Australia on account of its gold, the professors of Natural Science, in the Museum of Practical Geology, delivered a course of lectures in the summer of 1852. These lectures were as follows: 1. "The Geology of Australia, with Especial Reference to the Gold Regions,' by J. Beete Jukes, M.A. F.G.S., Local Director of the Geolo. gical Survey of Ireland; author of 'Sketch of the Physical Structure of Australia.' 2. On our Knowledge of Australian Rocks as derived from their Organic Remains,' by Edward Forbes, F.R.S. 3. The Chemical Properties of Gold, and the Mode of Distinguishing it from other Substances resembling it,' by Lyon Playfair, C.B. F.R.S. 4. The Dressing or Mechanical Preparation of Gold Ores,' by W. W. Smith, M.A. F.G.S. 5. The Metallurgical Treatment and Assaying of Gold Ores,' by John Percy, M.D. F.R.S. 6. "The History and Statistics of Gold,' by Robert Hunt, keeper of Mining Records. We subjoin an account of the auriferous rocks of Australia from the lecture of Mr. Jukes:- "Sir R. Murchison, in his address to the Geographical Society in 1844, alluded to the possibly auriferous character of the Great Eastern Chain of Australia, being led thereto by his knowledge of the auriferous chain of the Ural, and by his examination of Count Strzelecki's specimens, maps, and sections. Some of Sir R. Murchison's observations having found their way to the Australian papers, a Mr. Smith, at that time engaged in some iron works at Berrima, was induced by them in the year 1849 to search for gold, and he found it. He sent the gold to the Colonial government, and offered to disclose its locality on payment of 500l. The governor however not putting full faith in the statement, and being, moreover, unwilling to encourage a gold fever without sufficient reason, declined to grant the sum, but offered, if Mr. Smith would mention the locality, and the discovery was found to be valuable, to reward him accordingly. Very unwisely, as it turns out, Mr. Smith did not accept this offer; and it remained for Mr. Hargraves, who came with the prestige of his Californian experience, to re-make the discovery, and to get the reward from government on their own conditions. "This first discovery was made in the banks of the Summer Hill Creek and the Lewis Ponds River, small streams which run from the northern flank of the Conobalas down to the Macquarrie. The gold was found in the sand and gravel, accumulated especially on the inside of the bends of the brook, and at the junction of the two water-courses, where the stream of each would be often checked by the other. It was coarse gold, showing its parent site to be at no great distance, and probably in the quartz veins traversing the metamorphic rocks of the Conobalas. Mr. Stutchbury, the government geologist, reported on the truth of the discovery, and shortly afterwards found gold in several other localities, especially on the banks of the Turon, some distance north-east of the Conobalas. This was a much wider and more open valley than the Summer Hill Creek, and the gold accordingly was much finer, occurring in small scales and flakes. It was however more regularly and equably distributed through the soil, so that a man might reckon with the greater certainty on the quantity his daily labour would return him. At the head of the Turon River, among the dark glens and gullies in which it collects its head waters, in the flanks of the Blue Mountains, the gold got 'coarser,' occurring in larger lumps or nuggets, but these being more sparingly scattered. The reason of these circumstances, which are common to all auriferous regions, has been given in the former part of this Lecture when speaking of the power of moving water. "With the subsequent history of the 'gold diggings' of Australia, the discovery of many rich auriferous districts, both in New South Wales and Victoria, you must all be more or less familiar. "In Mr. Arrowsmith's map, appended to the Parliamentary Report just issued, all the auriferous spots are marked in yellow. They occur at intervals along the flanks of the Great Eastern Chain, or on its lateral spurs and subordinate ranges through an extent of country about 1000 miles in length, about as far as from London to Gibraltar or the confines of Turkey, or as from London to Iceland in a straight line. The principal localities marked on this map are Grafton Range and Burnet River, north of the Condamine; Stanley Creek and Canning Downs in the Moreton Bay district; several spots in the neighbourbood of Liverpool Plains; the Turon and Conobalas on the Macquarrie, below Bathurst; the Abercrombie River at the head of the Lachlan; some spots on each side of Breadalbane Plains; the Braidwood and Araluen diggings in the Shoalhaven district; Lake Eimeo in the Australian Alps; and Ballarat, and Mount Alexander and Mount Blackwood, north-west of Port Philip. "In every one of these localities granite and metamorphic rocks occur, and quartz veins are frequently spoken of. This is an important fact to bear in mind. "In scarcely any of them do we find mention made of the gold being seen in the actual rock, but in the drift clay, sand, and gravel, or lying loose on the surface of the ground. The hundredweight of gold, indeed, found by Dr. Ker north of Bathurst, is described as a block of highly auriferous quartz, lying among a lot of other loose blocks, evidently derived from a broad quartz vein running up the hill behind them. Such a mass, indeed, could hardly be transported far from its original site by any conceivable current of water. "The superficial drift in which the diggings have been carried on varies in thickness from a few inches to 20 or 30 feet. The following is an extract from a lecture given by a Mr. Gibbon, in Melbourne, and reported in the 'Melbourne Argus,' giving an account of the Ballarat diggings:-'On the surface of the earth was turf in a layer of about a foot thick, below which was a layer of rich black alluvial soil, and below that gray clay; below that again was a description of red gravel, which was sometimes very good; then red or yellow clay, in which gold was found; and then a stratum, varying in thickness, of clay streaked with various colours, and scarcely worth working; and the next stratum was of hard white pipe-clay, which was a decided barrier. Immediately above it however was a thin layer of chocolatecoloured clay, tough and soapy. This was the celebrated blue clay, and was very rich. "The ground or which the diggings were situated was a sloping My object to-night has been to give you such a rough sketch of the geology of Australia, and of the geological facts and principles that ought to guide any one in his search after gold, as may be of use to those intending to emigrate there. "In conclusion, I may perhaps be allowed to utter one word of advice. "Gold-digging is very hard work--just such work as you see navigators at in a railway cutting, or brick-makers in a brick-pit. You must work hard all day, lie hard all night, with but little shelter, often with scanty food, and with nothing of what you have probably been accustomed to consider necessary comfort. If you find you have no luck at the diggings, or if your health, or strength, or resolution fail you, do not therefore give up or despond altogether. You go out to dig for gold; do not be ashamed to dig for anything else. I speak to those now who have been hitherto unaccustomed to manual labour. Recollect, it is the avowed object of your voyage, and the only thing you have to trust to. If you fail to dig up gold there are lands to be ploughed, sheep to be herded and sheared, cattle to be tended, corn to be sown and reaped-every one of these fully as honourable occupations as digging for gold. Go, then, with a bold and resolute heart, determined to get your living by the strength of your own arms and the sweat of your own brows; and be assured, that industry and perseverance lead to fortune in Australia with fewer impediments and uncertainties in the way than in any part of the world." Since the above was written, other districts in Australia have yielded the precious metal, and every day is adding to our knowledge of the wide extension of this metal on the surface of the earth. A few months ago it was announced that gold had been discovered at the Cape of Good Hope; and at the beginning of the present year the late Dr. Stanger delivered a lecture at Natal, in which he pointed out the probability of gold being found in the neighbourhood of that colony. For an account of the Salts of Gold, and its applications in the arts and sciences, see GOLD, in ARTS AND SC. DIV. (Lectures on Gold delivered at the Museum of Practical Geology; GOLD OF PLEASURE. [CAMELINA.] GOLT, or GAULT, an argillaceous deposit, separating the upper greensand (also called firestone, malin-rock, &c.) from the lower greensand (also called Woburn sand, iron-sand, &c.). In Kent, Sussex, Surrey, the Isle of Wight, Wiltshire, and Cambridgeshire its geological situation and organic contents may be well studied. The clay of Speeton, on the Yorkshire coast, unites the characters of Golt and Kimmeridge Clay. [CHALK FORMATION.] GOMPHOLITE, a name given by M. Brongniart to conglomerate rocks of the Tertiary series, which in Switzerland are called Nägelflue. GOMPHONEMA. [DIATOMACEÆ.] GONIATITES, an extinct group of fossil shells, belonging to the division of Cephalopodous Mollusca. The species which it contains are usually arranged, by writers on organic remains, as a section of Ammonites; but their appropriate characters were never completely given till M. Von Buch, following Haan of Leyden, published his General Essay on the Sutures of Ammonites' (read to the Academy of Sciences at Berlin in April, 1830; translated in the 'Annales des Sciences Naturelles,' 1833). The families or genera of Nautili and Ammonites are seldom well understood by the conchological student, because the real distinctions between them are not the most apparent. The most constant of all the characters of Ammonites is the situation of the siphon, which, instead of perforating the disc of the transverse internal plates as in Nautilus, touches and lies parallel to the inner face of the shell on the dorsal line. There is another obvious and generally complete distinction in the form of the sutures, or intersections of the transverse |