Cl.CO.NH2, cyanuric acid (CONH)3, nascent cyanic acid,
or carbanile on hydrocarbons in the presence of aluminium
chloride, acid-amides being obtained which are readily
decomposed to give the acid. An important nucleus-synthetic
reaction is the saponification of nitriles, which may
be obtained by the interaction of potassium cyanide with
a halogen substitution derivative or a sulphonic acid.
Acids frequently result as oxidation products, being almost
invariably formed in all cases of energetic oxidation. There
are certain reactions, however, in which oxidation can be
successfully applied to the synthesis of acids. Thus primary
alcohols and aldehydes, both of the aliphatic and aromatic
series, readily yield on oxidation acids containing the same
number of carbon atoms. These reactions may be shown thus:-
R.CH2OH -> R.CHO -> R.CO.OH.
In the case of aromatic aldehydes, acids are also obtained
by means of ``Cannizzaro's reaction'' (see BENZALDEHYDE).
An important oxidation synthesis of aromatic acids is
from hydrocarbons with aliphatic side chains; thus toluene,
or methylbenzene, yields benzoic acid, the xylenes, or
dimethyl-benzene, yield methyl-benzoic acids and phthalic
acids. Ketones, secondary alcohols and tertiary alcohols
yield a mixture of acids on oxidation. We may also notice
the disruption of unsaturated acids at the double linkage
into a mixture of two acids, when fused with potash.
In the preceding instances the carboxyl group has been
synthesized or introduced into a molecule; we have now to
consider syntheses from substances already containing carboxyl
groups. Of foremost importance are the reactions termed the
malonic acid and the aceto-acetic ester syntheses; these are
discussed under their own headings. The electrosyntheses
call for mention here. It is apparent that metallic salts
of organic acids would, in aqueous solution, be ionized,
the positive ion being the metal, and the negative ion the
acid residue. Esters, however, are not ionized. It is
therefore apparent that a mixed salt and ester, for example
KO2C.CH2.CH2.CO2C2H5, would give only two ions, viz.
potassium and the rest of the molecule. If a solution of
potassium acetate be electrolysed the products are ethane,
carbon dioxide, potash and hydrogen; in a similar manner,
normal potassium succinate gives ethylene, carbon dioxide,
potash and hydrogen; these reactions may be represented:-
CH3.CO2 K CH3 CO2 K* CH2.CO K CH2 CO2 K.
| -> | + + | | ->|| + +
CH3.CO2 K CH3 CO2 K* CH2.CO K CH2 CO2 K.
By electrolysing a solution of potassium ethyl succinate,
KO2C.(CH2)2CO2C2H5, the KO2C. groups are split
off and the two residues .(CH2)2CO2C2H5 combine to
form the ester (CH2)4(CO2C2H5)2. In the same way,
by electrolysing a mixture of a metallic salt and an ester,
other nuclei may be condensed; thus potassium acetate and
potassium ethyl succinate yield CH3.CH2.CH2.CO2C2H5.
Reactions.--Organic acids yield metallic salts with bases,
and ethereal salts or esters (q.v.), R.CO.OR', with alcohols.
Phosphorus chlorides give acid chlorides, R.CO.Cl, the hydroxyl
group being replaced by chlorine, and acid anhydrides, (R.CO)2O,
a molecule of water being split off between two carboxyl
groups. The ammonium salts when heated lose one mobecule
of water and are converted into acid-amides, R.CO.NH2,
which by further dehydration yield nitriles, R.CN. The
calcium salts distilled with calcium formate yield aldehydes
(q.v.); distilled with soda-lime, ketones (q.v.) result.
ACIDALIUS, VALENS (1567-1595), German scholar and critic,
was born at Wittstock in Brandenburg. After studying at
Rostock, Grelfswald and Helmstedt, and residing about
three years in Italy, he settled at Breslau, where he is
said to have embraced the Roman Catholic religion. Early
in 1595 he accepted an invitation to Neisse, about fifty
miles from Breslau, where he died of brain fever on the
25th of May, at the age of twenty-eight. His excessive
application to study, and the attacks made upon him in
connexion with a pamphlet of which he was reputed the
author, doubtless hastened his premature end. Acidalius wrote
notes on Velleius Paterculus (1590), Curtius (1594), the
panegyrists, Tacitus and Plautus, published after his death.
See Leuschner, Commeutatio de A. V. Vita, Moribus,
et Scriptis (1757); F. Adam, ``Der Neisser Rektor,''
in Bericht der Philomathic in Neisse (1872).
ACID-AMIDES, chemical compounds which may be considered
as derived from ammonia by replacement of its hydrogen with
acidyl residues, the substances produced being known as
primary, secondary or tertiary amides, according to the
number of hydrogen atoms replaced. Of these compounds,
the primary amides of the type R.CO.NH2 are the most
important. They may be prepared by the dry distillation of
the ammonium salts of the acids (A. W. Hofmann, Ber., 1882,
15, p. 977), by the partial hydrolysis of the nitriles, by
the action of ammonia or ammonium carbonate on acid chlorides
or anhydrides, or by heating the esters (q.v.) with
ammonia. They are solid crystalline compounds (formamide
excepted) which are at first soluble in water, the solubility,
however, decreasing as the carbon content of the molecule
increases. They are easily hydrolysed, breaking up into
their components when boiled with acids or alkanes. They
form compounds with hydrochloric acid when this gas is
passed into their ethereal solution; these compounds,
however, are very unstable, being readily decomposed by
water. On the other hand, they show faintly acid properties
since the hydrogen of the amide group can be replaced
by metals to give such compounds as mercury acetamide
(CH3CONH)2Hg. Nitrous acid decomposes them, with elimination
of nitrogen and the formation of the corresponding acid,
RCO.NH2 + ONOH = R.COOH + N2 + H2O.
When distilled with phosphoric anhydride they yield
nitriles. By the action of bromine and alcoholic potash on
the amides, they are converted into amines containing one
carbon atom less than the original amide, a reaction which
possesses great theoretical importance (A. W. Hofmann),
R.CONH2 -> R.CONHBr -> R.NH2 + K2CO3 + KBr + H2O.
Formamide, H.CONH2, is a liquid readily soluble in water,
boillng at about 195 deg. C. with partial decomposition.
Acetamide, CH3.CONH2, is a white deliquescent crystalline
solid, which melts at 82-83 deg. C. and boils at 222 deg. C. It
is usually prepared by distilling ammonium acetate. It
is readily soluble in water and alcohol, but insoluble in
ether. Benzamide, C6H5.CONH2, crystallizes in leaflets
which melt at 130 deg. C. It is prepared by the action of
ammonium carbonate on benzoyl chloride. It yields a silver
salt which with ethyl iodide forms benzimidoethyl ether,
C6H5C: (NH).OC2H5, a behaviour which points to the
silver salt as being derived from the tautomeric imidobenzoic
acid, C6H5C: (NH).OH (J. Tafel, Ber., 1890, 23, p.
104). On the preparation of the substituted amides from
the corresponding sodamides see A. W. Titherley (Journ.
Chem. Soc., 1901, 59, p. 391). The secondary and tertiary
amides of the types (RCO)2NH and (RCO)3N may be prepared
by heating the primary amides or the nitriles with acids or
acid anhydrides to 200 deg. C. Thiamides of the type R.CSNH2
are known, and result by the addition of sulphuretted
hydrogen to the nitriles, or by the action of phosphorus
pentasulphide on the acid-amides. They readily decompose on
heating, and are easily hydrolysed by alkanes; they possess
a somewhat more acid character than the acid-amides.
ACINACES (from the Greek), an ancient Persian sword, short
and straight, and worn, contrary to the Roman fashion, on
the right side, or sometimes in front of the body, as shown
in the bas-reliefs found at Persepolis. Among the Persian
nobility it was frequently made of gold, being worn as a
badge of distinction. The acinaces was an object of religious
worship with the Scythians and others (Herod. iv. 62).
ACINETA (so named by C. G. Ehrenberg), a genus of suctorial
Infusoria characterized by the possession of a stalk and
cup-shaped sheath or theca for the body, and endogenous budding.
O. Butschli has separated off the genus Metacineta (for
A. mystacina), which reproduces by direct bud-fission.
ACINUS (Lat. for a berry), a term in botany applied to such
fruits as the blackberry or raspberry, composed of small
seedlike berries, and also to those berries themselves, or to
grapestones. By analogy, acinus is applied in anatomy
to similar granules or glands, or lobules of a gland.
ACIREALE, a town and episcopal see of the province of
Catania, Sicily; from the town of the same name it is distant 9
m. N. by E. Pop. (1901) 35,418. It has some importance as
a thermal station, and the springs were used by the Romans.
It takes its name from the river Acis, into which, according
to the legend, Acis, the lover of Galatea, was changed after
he had been slain by Polyphemus. The rocks which Polyphemus
hurled at Ulysses are identified with the seven Scogli de'
Ciclopi, or Faraglioni, a little to the south of Acireale.
ACIS, in Greek mythology, the son of Pan (Faunus) and the
nymph Syntaethis, a beautiful shepherd of Sicily, was the lover
of the Nereid Galatea. His rival the Cyclops Polyphemus
surprised them together, and crushed him to pieces with a rock.
His blood, gushing forth from beneath, was metamorphosed by
Galatea into the river bearing his name (now Fiume di Jaci),
which was celebrated for the coldness of its waters (Ovid,
Met. xiii. 750; Silius Italicus, Punica, xiv. 221).
ACKERMAN, FRANCIS (c. 1335--1387), Flemish soldier and
diplomatist, was born at Ghent, and about 1380 became prominent
during the struggle between the burghers of that town and
Louis II. (de Male), count of Flanders. He was partly
responsible for inducing Philip van Artevelde to become first
captain of the city of Ghent in 1382, and at the head of
some troops scoured the surrounding country for provisions
and thus saved Ghent from being starved into submission.
By his diplomatic abilities he secured the assistance of
the citizens of Brussels, Louvain and Liege, and, having
been made admiral of the Flemish fleet, visited England
and obtained a promise of help from King Richard II. After
Artevelde's death in November 1382, he acted as leader of the
Flemings, gained several victories and increased his fame by
skilfully conducting a retreat from Damme to Ghent in August
1385. He took part in the conclusion of the treaty of peace
between Ghent and Philip the Bold, duke of Burgundy, the
successor of Count Louis, in December 1385. Trusting in
Philip, and ignoring the warnings of his friends, Ackerman
remained in Flanders, and was murdered at Ghent on the 22nd
of July 1387, leaving a memory of chivalry and generosity.
See Jean Froissart, Chroniques, edited by S. Luce
and G. Raynaud (Paris, 1869-1897); Johannes Brandon,
Chronodromon, edited hy K. de Lettenhove in the
Chroniques rotatives a L'histoire de La Belgique sous
la domination des ducs de Bourgogne (Brussels, 1870).
ACKERMANN, JOHANN CHRISTIAN GOTTLIEB (1756-1801), German
physician, was born at Zeillenroda, in Upper Saxony, on the
17th of February 1756, and died at Altdorf on the 9th of March
1801. At the age of fifteen he became a student of medicine
at Jena under E. G. Baldinger, whom he followed to Gottingen
in 1773, and afterwards he studied for two years at Halle.
A few years' practice at Stendal (1778-1799), where there
were numerous factories, enabled him to add many valuable
