Page:EB1911 - Volume 01.djvu/953

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900

AMYGDALIN—AMYNTAS

along the Amur for 6½ months, from Khabarovsk to Stryetensk, on the Shilka terminus of the Trans-Siberian railway; but only light steamers with 2 to 3 ft. draught can navigate the upper Amur and Shilka. In the winter the frozen river is the usual highway. Rough roads and bridle-paths only are found in the interior. The great engineering difficulties in building a railway along the Amur induced the Russian government to obtain from China permission to build a railway through Manchuria, but the project for a railway from Khabarovsk to Stryetensk received imperial sanction in the summer of 1906. The Amur government has a continental climate, the yearly average at Blagovyeshchensk (50° N. lat.) being 30° Fahr. (January, 17°; July, 70°). It benefits from the influence of the monsoons. Cold north-west winds prevail from October to March, while in July and August torrential rains fall, resulting in a sudden and very considerable rise in the Amur and its right-bank tributaries. The only town is Blagovyeshchensk, but the centre of the administration is Khabarovsk in the Maritime province. The settled population in 1897 was 119,909, of whom 31,515 lived in towns.

The governor-generalship of Amur includes this government and the Maritime province, the total area being 888,830 sq. m., and the total population in 1897, 339,127. This region became known to the Russians in 1639. In 1649–1651 a party of Cossacks, under Khabarov, built a fort at Albazin on the Amur river, but in 1689 they withdrew in favour of the Chinese. From 1847 onwards they once more turned their attention to this region, and began to make settlements, especially after 1854, when a powerful flotilla sailed from Ust-Stryelka down to the mouth of the river. Four years later China ceded to Russia the whole left bank of the Amur, and also the right bank below the confluence of the Ussuri, and in 1860 all the territory between the Ussuri and the Eastern Sea.  (P. A. K.) 

AMYGDALIN (from the Gr. ἀμυγδάλη, almond), C20H27NO11, a glucoside isolated from bitter almonds by H. E. Robiquet and A. F. Boutron-Charlard in 1830, and subsequently investigated by Liebig and Wöhler, and others. It is extracted from almond cake by boiling alcohol; on evaporation of the solution and the addition of ether, amygdalin is precipitated as white minute crystals. Sulphuric acid decomposes it into d-glucose, benzaldehyde and prussic acid; while hydrochloric acid gives mandelic acid, d-glucose and ammonia. The decomposition induced by enzymes may occur in two ways. Maltase partially decomposes it, giving d-glucose and mandelic nitrile glucoside, C6H5CH(CN)O·C6H11O5; this compound is isomeric with sambunigrin, a glucoside found by E. E. Bourquelot and Danjou in the berries of the common elder, Sambucus nigra. Emulsin, on the other hand, decomposes it into benzaldehyde, prussic acid, and two molecules of glucose; this enzyme occurs in the bitter almond, and consequently the seeds invariably contain free prussic acid and benzaldehyde. An “amorphous amygdalin” is said to occur in the cherry-laurel. Closely related to these glucosides is dhurrin, C14H17O7N, isolated by W. Dunstan and T. A. Henry from the common sorghum or “great millet,” Sorghum vulgare; this substance is decomposed by emulsin or hydrochloric acid into d-glucose, prussic acid, and p-hydroxybenzaldehyde.


AMYGDALOID, a term meaning “almond-shaped,” used in anatomy and geology.

AMYL ALCOHOLS (C5H11OH). Eight amyl alcohols are known: normal amyl alcohol CH3·(CH2)4·OH, isobutyl carbinol or isoamyl alcohol (CH3)2·CH·CH2·CH2OH, active amyl alcohol (CH3)(C2H5):CH·CH2OH, tertiary butyl carbinol(CH3)3C·CH2OH, diethyl carbinol (C2H5)2CH·OH, methyl (n) propyl carbinol (CH3·CH2·CH2) (CH3):CH:OH, methyl isopropyl carbinol (CH3)2:CH(CH3):CHOH, and dimethyl ethyl carbinol (CH3)2·(C2H5)⫶C·OH. Of these alcohols, the first four are primary, the last one a tertiary, the other three secondary alcohols; three of them, viz. active amyl alcohol, methyl (n) propyl carbinol, and methyl isopropyl carbinol, contain an asymmetric carbon atom and can consequently each exist in two optically active, and one optically inactive form.

The most important is isobutyl carbinol, this being the chief constituent of fermentation amyl alcohol, and consequently a constituent of fusel (q.v.) oil. It may be separated from fusel oil by shaking with strong brine solution, separating the oily layer from the brine layer and distilling it, the portion boiling between 125° and 140°C. being collected. For further purification it may be shaken with hot milk of lime, the oily layer separated, dried with calcium chloride and fractionated, the fraction boiling between 128° and 132°C. only being collected. It may be synthetically prepared from isobutyl alcohol by conversion into isovaleryl-aldehyde, which is subsequently reduced to isobutyl carbinol by means of sodium amalgam.

It is a colourless liquid of specific gravity 0.8248 (0°C.), boiling at 131.6°C., slightly soluble in water, easily soluble in alcohol, ether, chloroform and benzene. It possesses a characteristic strong smell and a sharp burning taste. When perfectly pure, it is not a poison, although the impure product is. On passing its vapour through a red-hot tube, it undergoes decomposition with production of acetylene, ethylene, propylene, &c. It is oxidized by chromic acid mixture to isovaleryl-aldehyde; and it forms crystalline addition compounds with calcium and stannic chlorides.

The other amyl alcohols may be obtained synthetically. Of these, tertiary butyl carbinol has been the most difficult to obtain, its synthesis having only been accomplished in 1891, by L. Tissier (Comptes Rendus, 1891, 112, p. 1065) by the reduction of a mixture of trim ethyl acetic acid and trimethylacetyl chloride with sodium amalgam. It is a solid whichkmelts at 48°–50° C. and boils at 112.3° C.

AMYL NITRITE (isoamyl nitrite), C5H11·ONO, a liquid prepared by passing nitrous fumes (from starch and concentrated nitric acid) into warm isoamyl alcohol; or by distilling a mixture of 26 parts of potassium nitrite in 15 parts of water with 30 parts of isoamyl alcohol in 30 parts of sulphuric acid (Renard, Jahresb., 1874, p. 352). It is a yellow-coloured liquid of speciic gravity 0.877, boiling at about 95°–96° C. It has a characteristic penetrating odour, and produces marked effects on the system when its vapour is inhaled. It is insoluble in water, but dissolves readily in alcohol, ether, glacial acetic acid, chloroform and benzene. On heating with methyl alcohol it is converted into isoamyl alcohol, methyl nitrite being produced at the same time; a similar reaction takes place with ethyl alcohol, but the change is less complete. It is readily decomposed by nascent hydrogen, with the formation of ammonia and isoamyl alcohol; and on hydrolysis with caustic potash it forms potassium nitrite and isoamyl alcohol. When the liquid is dropped on to fused caustic potash, it forms potassium valerate. Amyl nitrite finds application in medicine, and in the preparation of anhydrous diazonium salts (E. Knoevenagel, Berichte, 1890, 23, p. 2094).

AMYMONE, in ancient Greek legend, daughter of Danaüs. With her sisters, she had been sent to look for water, the district of Argos being then parched through the anger of Poseidon. Amymone having thrown her spear at a stag, missed it, but hit a satyr asleep in the brake. The satyr pursued her, and she called for help on Poseidon, who appeared, and for love of her beauty caused a spring to well up, which received her name. Aeschylus wrote a satyric drama on the subject. By the god Amymone became the mother of Nauplius, the wrecker. Her meeting with Poseidon at the spring is frequently represented on ancient coins and gems.

Apollodorus ii. I, 4; Hyginus, Fab. 169; Propertius ii. 26.

AMYNTAS I., king of Macedonia (c. 540–498 B.C.), was a tributary vassal of Darius Hystaspes. With him the history of Macedonia may be said to begin. He was the first of its rulers to have relations with other countries; he entered into an alliance with the Peisistratidae, and when Hippias was driven out of Athens he offered him the territory of Anthemus on the Thermaic Gulf, with the object of turning the Greek party feuds to his own advantage (Herodotus v. 17, 94; Justin vii. 2; Thucydides ii. 100; Pausanias ix. 40). See Macedonian Empire.

AMYNTAS II. (or III.), son of Arrhidaeus, great-grandson of Alexander I., king of Macedonia from 393 (or 389) to 369 B.C.