and consists chiefly in the exercise of Christian love towards God and man. The seventh book, De Vita Beata, discusses, among a variety of subjects, the chief good, immortality, the second advent and the resurrection. Jerome states that Lactantius wrote an epitome of these Institutions, and such a work, which may well be authentic, was discovered in MS. in the royal library at Turin in 1711 by C. M. Pfaff.
Besides the Institutions Lactantius wrote several treatises: (1) De Ira Dei, addressed to one Donatus and directed against the Epicurean philosophy. (2) De Opificio Dei sive de Formatione Hominis, his earliest work, and one which reveals very little Christian influence. He exhorts a former pupil, Demetrianus, not to be led astray by wealth from virtue; and he demonstrates the providence of God from the adaptability and beauty of the human body. (3) A celebrated incendiary treatise, De Mortibus Persecutorum, which describes God’s judgments on the persecutors of his church from Nero to Diocletian, and has served as a model for numberless writings. De Mort. Persecut. is not in the earlier editions of Lactantius; it was discovered and printed by Baluze in 1679. Many critics ascribe it to an unknown Lucius Caecilius; there are certainly serious differences of grammar, style and temper between it and the writings already mentioned. It was probably composed in Nicomedia, c. 315. Jerome speaks of Lactantius as a poet, and several poems have been attributed to him:—De Ave Phoenice (which Harnack thinks makes use of 1 Clement), De Passione Domini and De Resurrectione (Domini) or De Pascha ad Felicem Episcopum. The first of these may belong to Lactantius’s heathen days, the second is a product of the Renaissance (c. 1500), the third was written by Venantius Fortunatus in the 6th century.
Editions: O. F. Fritzsche in E. G. Gersdorf’s Bibl. patr. eccl. x., xi. (Leipzig, 1842–1844); Migne, Patr. Lat. vi., vii.; S. Brandt and G. Laubmann in the Vienna Corpus Script. Eccles. Lat. xix., xxvii. 1 and 2 (1890–93–97). Translation: W. Fletcher in Ante-Nicene Fathers, vii. Literature: the German histories of early Christian literature, by A. Harnack, O. Bardenhewer, A. Ebert, A. Ehrhard, G. Kruger’s Early Chr. Lit. p. 307 and Hauck-Herzog’s Realencyk. vol. xi., give guides to the copious literature on the subject.
LACTIC ACID (hydroxypropionic acid), C3H6O3. Two lactic
acids are known, differing from each other in the position
occupied by the hydroxyl group in the molecule; they are
known respectively as α-hydroxypropionic acid (fermentation or
inactive lactic acid), CH3·CH(OH)·CO2H, and β-hydroxypropionic
acid (hydracrylic acid), (q.v.), CH2(OH)·CH2·CO2H. Although
on structural grounds there should be only two hydroxypropionic
acids, as a matter of fact four lactic acids are known. The third
isomer (sarcolactic acid) is found in meat extract (J. v. Liebig),
and may be prepared by the action of Penicillium glaucum on
a solution of ordinary ammonium lactate. It is identical with
α-hydroxypropionic acid in almost every respect, except with
regard to its physical properties. The fourth isomer, formed
by the action of Bacillus laevo-lacti on cane-sugar, resembles
sarcolactic acid in every respect, except in its action on polarized
light (see Stereoisomerism).
Fermentation, or ethylidene lactic acid, was isolated by K. W. Scheele (Trans. Stockholm Acad. 1780) from sour milk (Lat. lac, lactis, milk, whence the name). About twenty-four years later Bouillon Lagrange, and independently A. F. de Fourcroy and L. N. Vauquelin, maintained that Scheele’s new acid was nothing but impure acetic acid. This notion was combated by J. Berzelius, and finally refuted (in 1832) by J. v. Liebig and E. Mitscherlich, who, by the elementary analyses of lactates, proved the existence of this acid as a distinct compound. It may be prepared by the lactic fermentation of starches, sugars, gums, &c., the sugar being dissolved in water and acidified by a small quantity of tartaric acid and then fermented by the addition of sour milk, with a little putrid cheese. Zinc carbonate is added to the mixture (to neutralize the acid formed), which is kept warm for some days and well stirred. On boiling and filtering the product, zinc lactate crystallizes out of the solution. The acid may also be synthesized by the decomposition of alanine (α-aminopropionic acid) by nitrous acid (K. Strecker, Ann., 1850, 75, p. 27); by the oxidation of propylene glycol (A. Wurtz); by boiling α-chlorpropionic acid with caustic alkalis, or with silver oxide and water; by the reduction of pyruvic acid with sodium amalgam; or from acetaldehyde by the cyanhydrin reaction (J. Wislicenus, Ann., 1863, 128, p. 13)
It forms a colourless syrup, of specific gravity 1.2485 (15°/4°), and decomposes on distillation under ordinary atmospheric pressure; but at very low pressures (about 1 mm.) it distils at about 85° C., and then sets to a crystalline solid, which melts at about 18° C. It possesses the properties both of an acid and of an alcohol. When heated with dilute sulphuric acid to 130° C., under pressure, it is resolved into formic acid and acetaldehyde. Chromic acid oxidizes it to acetic acid and carbon dioxide; potassium permanganate oxidizes it to pyruvic acid; nitric acid to oxalic acid, and a mixture of manganese dioxide and sulphuric acid to acetaldehyde and carbon dioxide. Hydrobromic acid converts it into α-brompropionic acid, and hydriodic acid into propionic acid.
Lactide, O
CH(CH3·CO
CH·CH(CH3)
O,
a crystalline solid, of melting-point
124° C., is one of the products obtained by the distillation of lactic
acid.
LACTONES, the cyclic esters of hydroxy acids, resulting from
the internal elimination of water between the hydroxyl and
carboxyl groups, this reaction taking place when the hydroxy
acid is liberated from its salts by a mineral acid. The α and β-hydroxy
acids do not form lactones, the tendency for lactone
formation appearing first with the γ-hydroxy acids, thus γ-hydroxybutyric
acid, CH2OH·CH2·CH2·CO2H, yields γ-butyrolactone,
┌───────────┐
CH2·CH2·CH2·CO·O
These compounds may also be
prepared by the distillation of the γ-halogen fatty acids, or by
the action of alkaline carbonates on these acids, or from βγ- or
γδ-unsaturated acids by digestion with hydrobromic acid or
dilute sulphuric acid. The lactones are mostly liquids which
are readily soluble in alcohol, ether and water. On boiling
with water, they are partially reconverted into the hydroxy acids.
They are easily saponified by the caustic alkalis.
On the behaviour of lactones with ammonia, see H. Meyer, Monatshefte, 1899, 20, p. 717; and with phenylhydrazine and hydrazine hydrate, see R. Meyer, Ber., 1893, 26, p. 1273; L. Gattermann, Ber., 1899, 32, p. 1133, E. Fischer, Ber., 1889, 22, p. 1889.
γ-Butyrolactone is a liquid which boils at 206° C. It is miscible
with water in all proportions and is volatile in steam,
γ-valerolactone,
┌─────────────┐
CH3·CH·CH2·CH2·CO·O,
is a liquid which boils at 207-208°
C. δ-lactones are also known, and may be prepared by distilling
the δ-chlor acids.
LA CUEVA, JUAN DE (1550?–1609?), Spanish dramatist
and poet, was born at Seville, and towards 1579 began writing
for the stage. His plays, fourteen in number, were published
in 1588, and are the earliest manifestations of the dramatic
methods developed by Lope de Vega. Abandoning the Senecan
model hitherto universal in Spain, Cueva took for his themes
matters of national legend, historic tradition, recent victories
and the actualities of contemporary life: this amalgam of epical
and realistic elements, and the introduction of a great variety
of metres, prepared the way for the Spanish romantic drama
of the 17th century. A peculiar interest attaches to El Infamador,
a play in which the character of Leucino anticipates the classic
type of Don Juan. As an initiative force, Cueva is a figure
of great historical importance; his epic poem, La Conquista
de Bética (1603), shows his weakness as an artist. The last
work to which his name is attached is the Ejemplar poético
(1609), and he is believed to have died shortly after its
publication.
See the editions of Saco de Roma and El Infamador, by E. de Ochoa, in the Tesoro del teatro español (Paris, 1838), vol. i. pp. 251–285; and of Ejemplar poético, by J. J. López de Sedano, in the Parnaso español, vol. viii. pp. 1-68; also E. Walberg, “Juan de la Cueva et son Ejemplar poético” in the Acta Universitatis Lundensis (Lund, 1904), vol. xxix.; “Poèmes inédits de Juan de la Cueva (Viaje de Sannio,)” edited by F. A. Wulff, in the Acta Universitatis Lundensis (Lund, 1886–1887), vol. xxiii.; F. A. Wulff, “De la rimas de Juan de la Cueva, Primera Parte” in the Homenaje á Menéndez y Pelayo (Madrid, 1899), vol. ii. pp. 143–148. (J. F.-K.)
LACUNAR, the Latin name in architecture for a panelled
or coffered ceiling or soffit. The word is derived from lacuna,
a cavity or hollow, a blank, hiatus or gap. The panels or coffers
of a ceiling are by Vitruvius called lacunaria.
LACUZON (O. Fr. la cuzon, disturbance), the name given
to the Franc-Comtois leader Claude Prost (1607–1681), who
was born at Longchaumois (department of Jura) on the 17th
of June 1607. He gained his first military experience when
the French invaded Burgundy in 1636, harrying the French
