But we believe we are right in saying that such a gathering was no unusual event at Drayton, and that these and other men of similar attainments were the constant guests of the Prime Minister.

His patronage of literary men was usually discriminating. When he left office in 1835 he offered baronetcies to Mr. Southey and Mr. Barrow. He wrote to Wordsworth, to whom he was personally unknown, and asked him to tell him without reserve whether there is anything which I can 'do to gratify your present wishes or relieve you from anxiety ' about the future.' He conferred pensions on Mrs. Hemans, Mrs. Airy, Mrs. Somerville, Hogg, and Southey. In his later ministry he offered a baronetcy to Hallam; he conferred pensions on Tennyson, Wordsworth, Sir W. Hamilton, and he gave much-needed assistance to Haydon and Hood. Fortunate indeed was the minister who had such men to reward, but fortunate also was the country whose minister had the good sense and knowledge to make such a selection.

In the disposal of other honours he was equally discriminating. În five years he conferred only six peerages, and three of them-Ellenborough, Hardinge, and Gough-were for public services which no minister could have omitted to reward. He was equally cautious in the creation of baronetcies, and he even advised Sir James Graham 'to be as sparing as possible of knighthood. The distinction of 'being without an honour is becoming a rare and valuable 'one, and should not become extinct.' The cautious abstinence which he thus displayed increased his difficulties as a party leader. Ten years' exclusion from office,' so he told his brother-in-law, had brought him claims from half the 'gentry of the country to be made either peers or baronets.' And we can readily understand that these ambitious suitors were not reconciled to the minister-whose measures were threatening their rent rolls-by the reflexion that there was no prospect for them either of title or rank while he retained the prime ministership.

We have now endeavoured, so far as was possible in our narrow limits, to trace the leading incidents in Peel's career, and to weigh the worth of his services. In doing so we have been forced to exclude from our review all reference

Mr. Gladstone wrote, on this occasion, of Tennyson: 'It appears established that, though a true and even a great poet, he can hardly become a popular and is much more likely to be a starving one' (iii, p. 441).

to foreign affairs, as well as to the extremely interesting correspondence which Peel maintained with Lord Ellenborough and Sir H. Hardinge on India, and to confine ourselves rigidly and exclusively to his domestic policy. We have not attempted to conceal the defects in Peel's character, or his deficiencies as a party leader, and we have endeavoured to lay no undue stress on the great services which he rendered to his country. These services, indeed, do not require emphasising. The man who restored our credit, regulated our currency, reformed the criminal code, established the Metropolitan Police, promoted Free-trade, and gave us cheap bread, is in no need of an apology. On the whole, we can have very little doubt that the passions and the animosities which he provoked will gradually be forgotten, and that the achievements which he accomplished will alone be remembered. History will then record that, though Sir Robert Peel had not the eloquence of Chatham, the genius of Canning, or the foresight of Grey, he rendered services to the country which few prime ministers have equalled and none have excelled; and perhaps it may then recall the words which Carlyle wrote to him in 1846:—

'By and bye, as I believe, all England will say what already many a one begins to feel, that, whatever were the spoken unveracities in Parliament, and they are many on all hands, lamentable to Gods and men, here has a great veracity been done in Parliament, considerably our greatest for many years past, a strenuous, courageous, and manful thing, to which all of us that so see it are bound to give our loyal recognition, and such furtherance as we can.'

ART. II.-1. Diamonds. Lecture delivered at the Royal Institution, Friday, June 11, 1897. By Sir WILLIAM

CROOKES, F.R.S.

2. Papers and Notes on the Genesis and Matrix of the Diamond. By the late HENRY CARVILL LEWIS, M.A. Edited by Professor BONNEY, F.R.S. London: 1897.

3. Les Diamants du Cap. Par L. DE LAUNAY. Paris: 1897. 4. Les Mines de l'Afrique du Sud. Par ALBERT BORDEAUX, Ingénieur Civil des Mines. Paris: 1898.

5. Le Four Électrique. Par M. HENRI MOISSAN, de l'Institut.

Paris: 1897.

TH HE long-outstanding problem of the origin of diamonds is virtually solved. Their successful production in the laboratory has removed most of the doubts surrounding it. Cosa fatta capo ha.' With his crucibles full of gems, hot and hot from the furnace, the chemist can speak with authority. They are, it is true, of diminutive size, and, more often than not, shattered in the throes of birth; so that the prospect is remote of turning Institutes of Physical Research into Golconda-marts; yet their genuineness-take them for what they are worth-is equally incontestable with that of the Koh-i-noor itself.

The old familiar mode of occurrence of diamonds was as 'rolled pebbles.' In India, Borneo, Brazil, and Australia they form an ingredient of alluvial detritus, and are obviously flood-borne. Hence the phrases associating their qualities with water.' Gold was termed by Pliny their faithful 'companion;' and the traditional fellowship-often enough severed in modern experience-survives in the Paradise 'Lost' wherever purposes of ornament are in question, although for strength, as in the armour of Adramalech, the adamantine gem is employed alone. Diamonds, nevertheless, have usually a cortège of semi-precious stones-garnet, topaz, tourmaline, chalcedony; and a corresponding origin has sometimes been assigned to them. At first sight, the case seems plain. For they can, in Brazil, be tracked home to an ancient and dilapidated quartzite formation known as 'itacolumite,' a metamorphic rock, altered by heat, rent by earthquakes, fissured, grooved, eroded, injected with igneous products. Among these, in a qualified sense, the diamonds derived from it may be ranked. They are, undoubtedly, casual adjuncts to the original strata. Their place is among

the heterogeneous contents of vacuities in those transformed and tormented deposits. They are a minimal part of the breccia with which chasms have gradually become filled. There, as elsewhere, they are immigrants. Professor Gorlaix and Mr. Orville A. Derby satisfied themselves, indeed, in 1886 of their being 'vein-minerals.' Finding some small stones embedded in a decomposed ferruginous seam through an itacolumite ridge at São João de Chapada, in the province of Minas Geraes, they concluded them to have grown in mother-earth by the sublimation of carbon from the interior of the globe. For diamonds, however, such an origin is impossible. It is excluded-if no otherwise-by the single fact that they are non-adherent. None have ever been met with attached to any sort or kind of point d'appui. Each is essentially a free growth. None have flat or unfinished sides. They did not then at any time stand out like gargoyles in relief from plane surfaces.

The discovery of the dry diggings' in South Africa gave a completely new turn to ideas on the subject. This was in 1870, three years after a whitish pebble with a curious interior glimmer had been picked up in the bed of the Orange River, and taken to Cape Town by an Irish ostrichhunter. For in Griqualand West diamonds occur in 'washings,' as well as in mines, although the mines only are characteristic and peculiar. They are, indeed, among the most instructive geological phenomena in existence.

The great Karoo formation spreads like a mantle over two hundred thousand square miles of South Africa east and west from the Spitzkop to the Red Heights above Middleburg, north and south from the Black Mountains to the Vaal River. Its component beds were deposited at the bottom of an inland sea during the Triassic age, when the Labyrinthodon, or monster toad-lizard, led the van of creation; but their succession alternated with upwellings of molten basalt, which spread into level sheets intercalated between the carbonaceous shales representing the lacustrine ooze and the lacustrine vegetation of an all but endless epoch. They appear to have proceeded in comparative tranquillity, those copious lava-inundations. Vehement volcanic action was delayed until the complete stratification of the Karoo had been accomplished. Provoked, doubtless, by water-infiltrations to the smouldering volcanic foci beneath, tremendous explosions then took place, enormous

* Science, vol. ix. p. 57.

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volumes of gas were evolved, and, irresistibly expanding, perforated the superincumbent rocks with ample channels of escape. These did not remain empty. By spasmodic efforts most likely, not all at once nor all together, they were replenished from below. Of genuine igneous eruptions no traces remain; the work was done by mud-rushes transporting upwards miscellaneous subterranean débris, largely intermixed with floating reefs '-fragments, that is to say, torn from the circumjacent strata-the whole being agglutinated by tufaceous stuff into a volcanic breccia. This volcanic breccia is the blue ground' of Kimberley, the nidus of South African diamonds.

Such, apparently, is the history of these singular repositories. They are not, properly speaking, extinct craters, but rather gigantic blow-holes, excavated catastrophically, refilled gradually. The core materials in each pipe' represent several pours.' Obvious traces are encountered as they are dug out of variously conditioned inflows. There were no overflows. The treasure-laden breccia did not spread aboveground. In a few cases it failed to reach the surface, and the including shafts were masked by pans,' or depressions. The gours' of Auvergne, and the maare' of the Eiffel, are examples of similar volcanic chimneys left vacant, or merely water-filled.

The South African mines are not very numerous. Four lie clustered together at Kimberley within a diameter of less than four miles-the Kimberley, the De Beers, Dutoitspan, and Bulfontein. The Wesselton, opened later, belongs to the same group. The Leicester is on the Vaal, but inside the boundary line of Cape Colony; while the Orange Free State owns the diggings at Kaffeefontein and at Jagersfontein, where the magnificent thousand carat' stone known as the 'Excelsior' was disinterred five hours before the expiry of Messrs. Wernher, Beit, and Company's contract for the total yield from the works. All the shafts have clean-cut walls, testifying to the violence of the explosions by which they were created; and the uptilting of the black shales elsewhere horizontal-forming their masonry, tells the same story. They are, moreover, quite unchanged by metamorphic influences, so that the conclusion may bo reiterated that here gas-and-water eruptions only were concerned.

Among the mineral species brought upwards by them are olivine, augite, bronzite, garnet, mica, zircon, titanic and chromic iron. The absence of gold is noteworthy. Diamonds