LIME, ALUMINA, ETC., BORO-SILICATE OF.

Axinite. Found near Tavistock, at Brent Tor, with actinolite and garnet; also at Huel Friendship. Fine specimens occur at Sticklepath, near Okehampton, and in several places in the vicinity, such as Ivy Tor and Copper Hill mines, Huel Forest, Fursdon Manor Mine, and Meldon Quarry.

MAGNESIA.

MAGNESIA, LIME, AND IRON, SILICATE of.

Hornblende. Massive hornblende is common in the neighbourhood of Dartmoor. Hay Tor, Bovey Tracey, and Sticklepath afford good specimens. Several dykes of black hornblende occur in Lundy Island.

Actinolite is a fibrous or radiated variety of the above. It occurs frequently in the vicinity of Okehampton, as at Sticklepath, Ivy Tor Mine, and Huel Forest. Fine specimens occur at Brent Tor, near Tavistock, associated with garnet.

Asbestos. Another fibrous variety of hornblende. There are two specimens of it in the Museum of Practical Geology, Jermyn Street, which are described as occurring in fissures of the new red marl at Seaton, Devonshire. They were presented by Sir W. C. Trevelyan.

SILICA.

OXIDES OF SILICON.

Opal. Common opal is found at Hay Tor, on Dartmoor, Lustleigh, near Bovey, and near Okehampton.

Quartz. In beds or veins quartz is found more or less abundantly in every part of the county. Pseudomorphous after fluor in cubes and octahedrons at Beer Alston and South Hoo Mines, near Beer Ferris ; after calcite at Hay Tor Iron Mines.

The following are all varieties of quartz :—

Agate. Found at Mary Church, near Torquay; in pebbles at Sidmouth; and with rock crystal at Hay Tor.

Amethyst. Radiated at Whitchurch Down, near Tavistock. It is found also in the neighbourhood of Okehampton, and on Dart

moor.

Chalcedony. Stalactitic chalcedony has been found in the Beer Alston Mines. Fine botryoidal specimens occur at Hay Tor, where it is also met with pseudomorphous after calcite. It is also found near Sidmouth.

Chert is abundant on Haldon, near Exeter, and in the adjoining green sand district; also in the green sand at Orleigh Court, in the parish of Buckland Brewer, near Bideford.

Flint is found in the same localities and under the same conditions as chert; also at Sidmouth.

Haytorite consists of chalcedony in crystals, pseudomorphous after datholite. This is an extremely rare mineral, and only found at Hay Tor, on Dartmoor, whence it derives its name.

Hornstone occurs frequently in this county, as at the East Tamar Mine, Beer Ferris, and at Beer Alston, where it also is found pseudomorphous in the form of octahedral fluor.

Jasper is found at Ivy Bridge; Doddiscombleigh, near Chudleigh; Okehampton; Brent Tor, near Tavistock; and occasionally in the green sand at Buckland Brewer, near Bideford.

Rock Crystal. The finest crystals were discovered some years ago at Huel Friendship, near Tavistock. They were associated with chlorite, and occasionally attained the length of five or six inches. In the same neighbourhood crystals are found at Huel Betsy and other localities; also at Gidleigh, near Moreton Hampstead; Huel Robert, at Sampford Spiney; and near Okehampton. Large twin crystals are found at North Bovey. In the north of Devon small but very brilliant crystals occur imbedded in hematite at Georgeham and Viveham, near Barnstaple; also with pyrite at Combmartin. Very large crystals, sometimes of a black colour, have been found in the granite of Lundy Island.

STRONTIAN.

SULPHATE OF STRONTIAN.

Celestine. My only notice of the occurrence of this mineral in Devonshire is taken from Greg and Lettsom's Manual of Mineralogy, where it is described as found in transparent crystalline plates on gypsum at Sidmouth. It also is said to occur in flints in the same locality.

CLASS III.-CARBON AND ITS COMPOUNDS.

Anthracite. Thin intermittent beds of anthracite stretch eastwards from Abbotsham, on the shores of Barnstaple Bay, through Bideford in a straight line to Hawkridge Wood, near Umberleigh, a distance of about twelve miles. At Bideford the works, which have only recently been abandoned, are of very great antiquity, and extend for some distance underground. Sir H. De la Beche,* writing in 1838, states that the mines which were then at work produced in a short period from 600 to 700 tons of anthracite. From the western mine 1500 tons were raised during one year; * Report on the Geology of Cornwall, Devon, and West Somerset, p. 514.

whilst the eastern mine, when in full work, produced 58 tons per week. The bed, which has everywhere been removed by old workings to a depth of eight or ten fathoms, varies in thickness from six inches to fourteen feet, the average being seven feet.

The culm or anthracite at Tawstock is mentioned by Polwhele in 1797; and Lysons* describes the works as being extensively carried on about the middle of the last century. After being abandoned for a time they were re-opened about 1790, and ten years later they produced 900 bushels per week, the depth of the pit being then about 25 fathoms. There were two veins, about

nine feet in thickness.

Lignite, or Bovey Coal. The lignite of Bovey Tracey is so well known, that it is unnecessary to do more than refer to it; and so numerous have been the papers on the subject read before the principal scientific societies, that its history alone would occupy a considerable space. For a description of the lignite deposit, including the intercalated clay beds, see Mr. Pengelly's interesting paper in the first report of this Association.

MINERAL RESINS.

Bitumen. Found many years ago at Chudleigh with apatite; also at Huel Crebor, near Tavistock.

Petroleum, a semifluid variety of the above, has been found at Chudleigh.

Retinite, or Retinasphaltum. In yellowish brown masses, with an earthy texture. Accompanies lignite at Bovey Tracey.

* Magna Britannia, vol. vi. p. 292.

THE SCIENCE OF HISTORY.

BY J. ERSKINE RISK, M.A.

OUR neighbours on the continent, who often flatter themselves on having got the start of the children of perfidious Albion, have for some time plumed themselves on having obtained the key to a science, the very existence of which is far from clear to most of our English philosophers. That so-called science is "the science of history. "The sole foundation for belief in the natural sciences," says Condorcet,* "is this notion that the general laws, known or unknown, which govern the phenomena of the universe, are necessary and constant. And why should this principle be less true for the development of the intellectual and moral faculties of man than for the other operations of nature?" (Simply because they are not in pari materia.) "Finally," he goes on to say, "since opinions formed after experience are the only rule of conduct of the wisest men, why should the philosopher be forbidden to rest his conjectures on the same basis, provided he does not attribute to them a certainty superior to that which may arise out of the number, constancy, and exactness of his observations?" Just so. But conjectures of such limited certainty can hardly form the basis of a true science. The question then proposed to us by continental philosophers, and echoed to us from them by a few of our own writers, is just this: Is not a science of history possible? If physical phenomena may be regarded as being governed by fixed and necessary laws, may not moral and social phenomena be proved to be subject to the same rule? There are upon this subject two widely separated schools of thought the necessarian and the libertarian; while to these may be added a third or intermediate school, which, attempting to effect a compromise between both the former, borrows from each only so much as may make its own position tenable, forgetful all the while that thus it abdicates for its

Esquisse d'un Tableau Historique des Progrès de l'Esprit Humain."

favourite study the position of a science. Stuart Mill, in his exposition of the necessarian doctrine, is, I must remind you, particularly careful to prevent its being confounded with fatalism; a mistake which, even by his own showing, must be a very natural one to fall into. According to this writer, "the true necessarian doctrine is, that whatever is about to happen will be the infallible result of the causes which produce it;" while fatalism maintains that "it is of no use struggling to prevent it-it will happen, however we may strive to prevent it." And yet, as Mill admits, that when a necessarian comes to believe that our actions follow from our characters, he holds that these again are the inevitable result of organization, education, and circumstances, it seems only fair for such a one to come to the conclusion that his nature is now so formed that he cannot act otherwise than he is in the habit of acting. Mill indeed attempts to escape from this vicious circle, and complains most pathetically of being misunderstood by those who insist that "this great doctrine," as he calls it, means that a man's character is not made by him, but for him. But the way in which he seeks to evade the dilemma is not, at least to me, satisfactory. "We are exactly as capable of making our own character, if we will, as others are of making it for us." The element of will, you will observe, is thus introduced to prevent necessarianism from lapsing into fatalism; but that is precisely the point for which the second school, or the Libertarians, contend. It is in vain that Mill endeavours to explain away the concession he is thus forced to make, by the assertion of the identity of the will to form one's character with the wish so to form it. The wish, he would have us believe, arises, not from our organization, but from experience-experience either of the painful consequences of our former character, or "some strong feeling of admiration or aspiration accidentally aroused." In other words, the wish for reformation arises either from some sense of pain, or some accidental longing. It is either the result of circumstances beyond our control, or some chance medley of desire; both of which causes-whether the necessary or the accidental one-however, would, according to his theory, be equally governed by his invariable sequence of events, and so by limiting the real operation of the will reduce the necessarian under the yoke of fatalism. When, moreover, you remember that Mill quotes with approbation the saying of Novalis, that "character is a completely fashioned will" —a will, i.e., completely fashioned by organization, education, and circumstance, his attempt to relieve the necessarian from