that elapsed before his admission to the English bar in 1807 with researches in law, philosophy and political economy. In February 1806 he became one of the commissioners for adjusting the claims against the nawab of Arcot, and in November entered parliament as member for St Ives. Next year he sat. for Wendover, and in 1812 for St Mawes, in the patronage of the marquis of Buckingham. In 1811, when Lord Grenville was organizing a prospective ministry, Horner had the offer, which he refused, of a treasury secretaryship. He had resolved not to accept office till he could afford to live out of office; and his professional income, on which he depended, was at no time proportionate to his abilities. His labours at last began to tell upon a constitution never robust, and in October 1816 his physicians ordered him to Italy, where, however, he sank under his malady. He died at Pisa, on the 8th of February 1817. He was buried at Leghorn, and a marble statue by Chantrey was erected to his memory in Westminster Abbey.
Without the advantages of rank, or wealth, or even of genius, Francis Horner rose to a high position of public influence and private esteem. His special field was political economy. Master of that subject, and exercising a sort of moral as well as intellectual influence over the House of Commons he, by his nervous and earnest rather than eloquent style of speaking, could fix its attention for hours on such dry topics as finance, and coinage, and currency. As chairman of the parliamentary committee for investigating the depreciation of bank-notes, for which he moved in 1810, he extended and confirmed his fame as a political economist by his share in the famous Bullion Report. It was chiefly through his efforts that the paper-issue of the English banks was checked, and gold and silver reinstated in their true position as circulating media; and his views on free trade and commerce have been generally accepted at their really high value. Horner was one of the promoters of the Edinburgh Review in 1802. His articles in the early numbers of that publication, chiefly on political economy, form his only literary legacy.
See Memoirs and Correspondence of Francis Horner, M.P., published by his brother (see below) in 1843. Also the Edinburgh and Quarterly Reviews for the same year; and Blackwood’s Magazine, vol. i.
HORNER, LEONARD (1785–1864), Scottish geologist, brother
of Francis Horner (above), was born in Edinburgh on the 17th
of January 1785. His father, John Horner, was a linen merchant
in Edinburgh, and Leonard, the third and youngest son, entered
the university of Edinburgh in 1799. There in the course of the
next four years he studied chemistry and mineralogy, and
gained a love of geology from Playfair’s Illustrations of the
Huttonian Theory. At the age of nineteen he became a partner
in a branch of his father’s business, and went to London. In
1808 he joined the newly formed Geological Society and two
years later was elected one of the secretaries. Throughout his
long life he was ardently devoted to the welfare of the society;
he was elected president in 1846 and again in 1860. In 1811
he read his first paper “On the Mineralogy of the Malvern Hills”
(Trans. Geol. Soc. vol. i.) and subsequently communicated other
papers on the “Brine-springs at Droitwich,” and the “Geology
of the S.W. part of Somersetshire.” He was elected F.R.S.
in 1813. In 1815 he returned to Edinburgh to take personal
superintendence of his business, and while there (1821) he was
instrumental in founding the Edinburgh School of Arts for
the instruction of mechanics, and he was one of the founders
of the Edinburgh Academy. In 1827 he was invited to London
to become warden of the London University, an office which he
held for four years; he then resided at Bonn for two years and
pursued the study of minerals and rocks, communicating to the
Geological Society on his return a paper on the “Geology of the
Environs of Bonn,” and another “On the Quantity of Solid
Matter suspended in the Water of the Rhine.” In 1833 he was
appointed one of the commissioners to inquire into the employment
of children in the factories of Great Britain, and he was
subsequently selected as one of the inspectors. In later years
he devoted much attention to the geological history of the
alluvial lands of Egypt; and in 1843 he published his Life of
his brother Francis. He died in London on the 5th of March
1864.
See Memoir of Leonard Horner, by Katherine M. Lyell (1890) (privately printed).
HÖRNES, MORITZ (1815–1868), Austrian palaeontologist,
was born in Vienna on the 14th of July 1815. He was educated
in the university and graduated Ph.D. He then became assistant
in the Vienna mineralogical museum. He was distinguished
for his researches on the Tertiary mollusca of the Vienna Basin,
and on the Triassic mollusca of Alpine regions. Most of his
memoirs were published in the Jahrbuch der K. K. geol. Reichsanstalt.
In 1864 he introduced the term Neogene to include
Miocene and Pliocene, as these formations are not always to
be clearly separated: the fauna of the lower division being
subtropical and gradually giving place in the upper division to
Mediterranean forms. He died in Vienna on the 4th of November
1868. His son Dr Rudolf Hörnes (b. 1850), professor of geology
and palaeontology in the university of Graz, has also carried on
researches among the Tertiary mollusca, and is author of Elemente
der Palaeontologie (1884).
HORNFELS (a German word meaning hornstone), the group
designation for a series of rocks which have been baked and
indurated by the heat of intrusive granitic masses and have
been rendered massive, hard, splintery, and in some cases
exceedingly tough and durable. Most hornfelses are fine-grained,
and while the original rocks (such as sandstone, shale and slate,
limestone and diabase) may have been more or less fissile owing
to the presence of bedding or cleavage planes, this structure is
effaced or rendered inoperative in the hornfels. Though they
may show banding, due to bedding, &c., they break across this
as readily as along it; in fact they tend to separate into cubical
fragments rather than into thin plates. The commonest hornfelses
(the “biotite hornfelses”) are dark-brown to black with a
somewhat velvety lustre owing to the abundance of small crystals
of shining black mica. The “lime hornfelses” are often white,
yellow, pale-green, brown and other colours. Green and dark-green
are the prevalent tints of the hornfelses produced by the
alteration of igneous rocks. Although for the most part the
constituent grains are too small to be determined by the unaided
eye, there are often larger crystals of garnet or andalusite
scattered through the fine matrix, and these may become very
prominent on the weathered faces of the rock.
The structure of the hornfelses is very characteristic. Very rarely do any of the minerals show crystalline form, but the small grains fit closely together like the fragments of a mosaic; they are usually of nearly equal dimensions and from the resemblance to rough pavement work this has been called pflaster structure or pavement structure. Each mineral may also enclose particles of the others; in the quartz, for example, small crystals of graphite, biotite, iron oxides, sillimanite or felspar may appear in great numbers. Often the whole of the grains are rendered semi-opaque in this way. The minutest crystals may show traces of crystalline outlines; undoubtedly they are of new formation and have originated in situ. This leads us to believe that the whole rock has been recrystallized at a high temperature and in the solid state, so that there was little freedom for the mineral molecules to build up well-individualized crystals. The regeneration of the rock has been sufficient to efface most of the original structures and to replace the former minerals more or less completely by new ones. But crystallization has been hampered by the solid condition of the mass and the new minerals are formless and have been unable to reject impurities, but have grown around them.
Slates, shales and clays yield biotite hornfelses in which the most conspicuous mineral is black mica, in small scales which under the microscope are transparent and have a dark reddish-brown colour and strong dichroism. There is also quartz, and often a considerable amount of felspar, while graphite, tourmaline and iron oxides frequently occur in lesser quantity. In these biotite hornfelses the minerals, which consist of aluminium silicates, are commonly found; they are usually andalusite and
