which it is most reasonable broadly to divide mankind they may be analysed as to their racial constituents and their habitats as follows:—
1. Caucasic or White Man is best divided, following Huxley, into (a) Xanthochroi or “fair whites” and (b) Melanochroi or “dark whites.” (a) The first—tall, with almost colourless skin, blue or grey eyes, hair from straw colour to chestnut, and skulls varying as to proportionate width—are the prevalent inhabitants of Northern Europe, and the type may be traced into North Africa and eastward as far as India. On the south and west it mixes with that of the Melanochroi and on the north and east with that of the Mongoloids. (b) The “dark whites” differ from the fair whites in the darkening of the complexion to brownish and olive, and of the eyes and hair to black, while the stature is somewhat lower and the frame lighter. To this division belong a large part of those classed as Celts, and of the populations of Southern Europe, such as Spaniards, Greeks and Arabs, extending as far as India, while endless intermediate grades between the two white types testify to ages of intermingling. Besides these two main types, the Caucasic division of mankind has been held with much reason to include such aberrant types as the brown Polynesian races of the Eastern Pacific, Samoans, Hawaiians, Maoris, &c., the proto-Malay peoples of the Eastern archipelago, sometimes termed Indonesians, represented by the Dyaks of Borneo and the Battaks of Sumatra, the Todas of India and the Ainus of Japan.
2. Mongolic or Yellow Man prevails over the vast area lying east of a line drawn from Lapland to Siam. His physical characteristics are a short squat body, a yellowish-brown or coppery complexion, hair lank, straight and black, flat small nose, broad skull, usually without prominent brow-ridges, and black oblique eyes. Of the typical Mongolic races the chief are the Chinese, Tibetans, Burmese, Siamese; the Finnic group of races occupying Northern Europe, such as Finns, Lapps, Samoyedes and Ostyaks, and the Arctic Asiatic group represented by the Chukchis and Kamchadales; the Tunguses, Gilyaks and Golds north of, and the Mongols proper west of, Manchuria; the pure Turkic peoples and the Japanese and Koreans. Less typical, but with the Mongolic elements so predominant as to warrant inclusion, are the Malay peoples of the Eastern archipelago. Lastly, though differentiated in many ways from the true Mongol, the American races from the Eskimo to the Fuegians must be reckoned in the Yellow division of mankind.
3. Negroid or Black Man is primarily represented by the Negro of Africa between the Sahara and the Cape district, including Madagascar. The skin varies from dark brown to brown-black, with eyes of the same colour, and hair usually black and always crisp or woolly. The skull is narrow, with orbital ridges not prominent, the jaws protrude, the nose is flat and broad, and the lips thick and everted. Two important families are classed in this division; some authorities hold, as special modifications of the typical Negro to-day, others as actually nearer the true generalized Negroid type of neolithic times. First are the Bushman of South Africa, diminutive in stature and of a yellowish-brown colour: the neighbouring Hottentot is believed to be the result of crossing between the Bushman and the true Negro. Second are the large Negrito family, represented in Africa by the dwarf races of the equatorial forests, the Akkas, Batwas, Wochuas and others, and beyond Africa by the Andaman Islanders, the Aetas of the Philippines, and probably the Senangs and other aboriginal tribes of the Malay Peninsula. The Negroid type seems to have been the earliest predominant in the South Sea islands, but it is impossible to say certainly whether it is itself derived from the Negrito, or the latter is a modification of it, as has been suggested above. In Melanesia, the Papuans of New Guinea, of New Caledonia, and other islands, represent a more or less Negroid type, as did the now extinct Tasmanians.
Excluded from this survey of the grouping of Man are the aborigines of Australia, whose ethnical affinities are much disputed. Probably they are to be reckoned as Dravidians, a very remote blend of Caucasic and Negro man. For a detailed discussion of the branches of these three main divisions of Man the reader must refer to articles under race headings, and to Negro; Negritos; Mongols; Malays; Indians, North American; Australia; Africa; &c., &c.
Bibliography.—J. C. Prichard, Natural History of Man (London, 1843), Researches into the Physical History of Mankind (5 vols., 1836–1847); T. H. Huxley, Man’s Place in Nature (London, 1863), and “Geographical Distribution of Chief Modifications of Mankind,” in Journ. Anthropological Institute for 1870; Theodore Waitz, Anthropologie der Naturvölker (1859–1871); A. de Quatrefages, Histoire générale des races humaines (Paris, 1889); E. B. Tylor, Anthropology (1881); Lord Avebury, Prehistoric Times (1865; 6th ed., 1900) and Origin of Civilization (1870; 6th ed., 1902); F. Ratzel, History of Mankind (Eng. trans., 1897); A. H. Keane, Ethnology (2nd ed., 1897), and Man: Past and Present (2nd ed., 1899); G. de Mortillet, Le Préhistorique (Paris, 1882; 3rd ed., 1900); D. G. Brinton, Races and Peoples (1890); J. Deniker, The Races of Man (London, 1900); Hutchinson’s Living Races of Mankind (1906).
ETHYL, in chemistry, the name given to the alkyl radical
C2H5. The compounds containing this radical are treated
under other headings; the hydride is better known as ethane,
the alcohol, C2H5OH, is the ordinary alcohol of commerce, and
the oxide (C2H5)2O is ordinary ether.
ETHYL CHLORIDE, or Hydrochloric Ether, C2H5Cl, a
chemical compound prepared by passing dry hydrochloric acid
gas into absolute alcohol. It is a colourless liquid with a sweetish
burning taste and an agreeable odour. It is extremely volatile,
boiling at 12.5° C. (54.5° F.), and is therefore a gas at ordinary
room temperatures; it is stored in glass tubes fitted with screw-capped
nozzles. The vapour burns with a smoky green-edged
flame. It is largely used in dentistry and slight surgical operations
to produce local anaesthesia (q.v.), and is known by the
trade-name kelene. More volatile anaesthetics such as anestile
or anaesthyl and coryl are produced by mixing with methyl
chloride; a mixture of ethyl and methyl chlorides with ethyl
bromide is known as somnoform.
ETHYLENE, or Ethene, C2H4, or H2C:CH2, the first representative
of the series of olefine hydrocarbons, is found in coal
gas. It is usually prepared by heating a mixture of ethyl alcohol
and sulphuric acid. G. S. Newth (Jour. Chem. Soc., 1901, 79,
p. 915) obtains a purer product by dropping ethyl alcohol into
syrupy phosphoric acid (sp. gr. 1.75) warmed to 200° C., subsequently
raising the temperature to 220° C. It can also be
obtained by the action of sodium on ethylidene chloride (B.
Tollens, Ann., 1866, 137, p. 311); by the reduction of copper
acetylide with zinc dust and ammonia; by heating ethyl
bromide with an alcoholic solution of caustic potash; by passing
a mixture of carbon bisulphide and sulphuretted hydrogen over
red-hot copper; and by the electrolysis of a concentrated solution
of potassium succinate,
It is a colourless gas of somewhat sweetish taste; it is slightly soluble in water, but more so in alcohol and ether. It can be liquefied at −1.1° C., under a pressure of 4212 atmos. It solidifies at −181° C. and melts at −169° C. (K. Olszewski); it boils at −105° C. (L. P. Cailletet), or −102° to −103° C. (K. Olszewski). Its critical temperature is 13° C., and its specific gravity is 0.9784 (air = 1). The specific gravity of liquid ethylene is 0.386 (3° C.). Ethylene burns with a bright luminous flame, and forms a very explosive mixture with oxygen. For the combustion of ethylene see Flame. On strong heating it decomposes, giving, among other products, carbon, methane and acetylene (M. Berthelot, Ann., 1866, 139, p. 277). Being an unsaturated hydrocarbon, it is capable of forming addition products, e.g. it combines with hydrogen in the presence of platinum black, to form ethane, C2H6, with sulphur trioxide to form carbyl sulphate, C2H4(SO3)2, with hydrobromic and hydriodic acids at 100° C. to form ethyl bromide, C2H5Br, and ethyl iodide, C2H5I, with sulphuric acid at 160–170° C. to form ethyl sulphuric acid, C2H5·HSO4, and with hypochlorous acid to form glycol chlorhydrin, Cl·CH2·CH2·OH. Dilute potassium permanganate solution oxidizes it to ethylene glycol, HO·CH2·CH2·OH, whilst fuming nitric acid converts it into oxalic acid. Several compounds of ethylene and metallic
