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upon the mucous membrane of the stomach, from which there come in large part those organic sensations which we interpret as hunger. Hence it is possible, under the influence of coca, to go without food or consciousness of needing it, for as long a period as three days. The drug is not a food, however, as its composition and history in the body clearly show, and the individual who comfortably fasts under its influence nevertheless shows all the physical signs of starvation, such as loss of weight. In small doses coca stimulates the intestinal peristalsis and thus is an aperient, but in large doses it paralyses the muscular coat of the bowel, causing constipation, such as is constantly seen in coco-maniacs, and in those inhabitants of Peru and the adjacent countries who take it in excess or are markedly susceptible to its influence.

The injection of coca leaves has a very remarkable effect upon the higher tracts of the nervous system—an effect curiously contrary to that produced by their chief ingredient upon the peripheral parts of the nervous apparatus. The mental power is, at any rate subjectively, enhanced in marked degree. In the absence of extended experiments in psychological laboratories, such as have been conducted with alcohol, it is not possible to say whether the apparent enhancement of the intellect is an objectively demonstrable fact. The physical power is unquestionably increased, such muscular exercises as are involved in ascending mountains being made much easier after the chewing of an ounce or so of these leaves. Excess in coca-chewing leads in many cases to great bodily wasting, mental failure, insomnia, weakness of the circulation and extreme dyspepsia. For other pharmacological characters and the therapeutic employments of coca see Cocaine.

COCAINE, C17H21NO4, an alkaloid occurring to the extent of about 1% in the leaves of Erythroxylon coca (see above). It is associated with many other alkaloids: cinnamyl cocaine, C19H23NO4; α-truxilline, (C19H23NO4)2; β-truxilline, (C19H23NO4)2; benzoylecgonine, C16H19NO2; tropa-cocaine, C15H19NO2; hygrine, C8H15NO; cuscohygrine, C13H24NO2. These substances, which may be collectively termed “cocaines,” are all derivatives of ecgonine (q.v.). Cocaine is benzoylmethyl ecgonine. It crystallizes from alcohol in prisms, which are sparingly soluble in water. Its solution has a bitter taste, alkaline reaction, and is laevorotatory. Its use as a local anaesthetic (see Anaesthesia) makes it the most valuable of the coca alkaloids, and it is much used in ophthalmic practice. Applied to the conjunctiva it causes anaesthesia, dilatation of the pupil, diminution of the intraocular tension, and some interference with accommodation. The conversion of the mixture obtained by extracting coca-leaves into cocaine is effected by saponifying the esters into ecgonine and the respective acids, and then benzoylating and methylating the ecgonine. Homologues of cocaine—ethylbenzoylecgonine, &c.—have been prepared; they closely resemble natural cocaine. Cinnamyl cocaine is cinnamylmethylecgonine, i.e. cocaine in which the benzoyl group is replaced by the cinnamyl group. α- and β-truxillines, named from their isolation from a coca of Truxillo (Peru), are two isomeric alkaloids which hydrolyse to ecgonine, methyl alcohol, and two isomeric acids, the truxillic acids, C18H16O4. The alkaloids are therefore methyl truxillylecgonines. The truxillic acids have been studied by K. Liebermann and his students (Ber., vols. 21-27, and 31), and are diphenyl tetramethylene dicarboxylic acids.

COCANADA, or Coconada, a town of British India, in the Godavari district of Madras, on the coast in the extreme north of the Godavari delta, about 315 m. N. of Madras. Pop. (1901) 48,096, showing an increase of 18% in the decade. As the administrative headquarters of the district, and the chief port on the Coromandel coast after Madras, Cocanada was formerly of considerable importance, but its shipping trade has declined, owing to the silting of the anchorage, and to the construction of the railway. It is connected by navigable channels with the canal system of the Godavari delta, and by a branch line with Samalkot on the East Coast railway. The anchorage is an open roadstead, with two lighthouses. The chief exports are rice, cotton, sugar and oilseeds. Mills have been established for cleaning rice. The town contains a second-grade college, a high school, and a literary association.

COCCEIUS [strictly Koch], JOHANNES (1603–1669), Dutch theologian, was born at Bremen. After studying at Hamburg and Franeker, where Sixtinus Amama was one of his teachers, he became in 1630 professor of biblical philology at the “Gymnasium illustre” in his native town. In 1636 he was transferred to Franeker, where he held the chair of Hebrew, and from 1643 the chair of theology also, until 1650, when he succeeded Fr. Spanheim the elder as professor of theology at Leiden. He died on the 4th of November 1669. His chief services as an oriental scholar were in the department of Hebrew philology and exegesis. As one of the leading exponents of the “covenant” or “federal” theology, he spiritualized the Hebrew scriptures to such an extent that it was said that Cocceius found Christ everywhere in the Old Testament and Hugo Grotius found him nowhere. He taught that before the Fall, as much as after it, the relation between God and man was a covenant. The first covenant was a “Covenant of Works.” For this was substituted, after the Fall, the “Covenant of Grace,” to fulfil which the coming of Jesus Christ was necessary. He held millenarian views, and was the founder of a school of theologians who were called after him Cocceians. His theology was founded entirely on the Bible, and he did much to promote and encourage the study of the original text. In one of his essays he contends that the observance of the Sabbath, though expedient, is not binding upon Christians, since it was a Jewish institution. His most distinguished pupil was the celebrated Campeius Vitringa. His most valuable work was his Lexicon et Commentarius Sermonis Hebraici et Chaldaici (Leiden, 1669), which has been frequently republished; his theology is fully expounded in his Summa Doctrinae de Foedere et Testamento Dei (1648).

His collected works were published in 12 folio volumes (Amsterdam, 1673–1675). See Herzog-Hauck, Realencyklopädie.

COCCIDIA, an important order of Sporozoa Ectospora, parasites possessing certain very distinctive characters. With one or two possible exceptions, they are invariably intracellular during the entire trophic life of the individual. They always attack tissue-cells, usually of an epithelium, and never blood-corpuscles. Correlated with the advanced degree of parasitism, there is a complete absence of specialization or differentiation of the cell-body, and the trophozoite is quite incapable of any kind of movement. In all cases, so far as known, the life-cycle is digenetic, an asexual generation (produced by schizogony) alternating with a sexual one (gametogony). After conjugation of two highly-differentiated gametes has taken place, a resistant oocyst is formed, which provides for the dispersal of the species; inside this sporogony (spore- and sporozoite-formation) goes on.

Hake (1839) was, perhaps, the first to describe a Coccidian, but he regarded the parasites as pathological cell-products. In 1845 N. Lieberkühn pointed out the resemblances to Gregarines, with which organisms he considered History. Coccidia to be allied. A year later, H. Kloss proved the existence of similar parasites in the snail, and attempted to construct their life-history; this form was subsequently named Klossia helicina by A. Schneider. The asexual part of the life-cycle was first described by Th. Eimer in 1870, for a Coccidian infesting the mouse, which was afterwards elevated by Schneider into a distinct genus Eimeria. The generic name Coccidium was introduced by R. Leuckart in 1879, for the parasite of the rabbit. It was many years, however, before the double character of the life-cycle was realized, and the ideas of L. and R. Pfeiffer, who first suggested the possibility of an alternation of generations, for a long time found no favour. In the first decade of the 20th century great progress was accomplished, thanks largely to the researches of F. Schaudinn and M. Siedlecki, who first demonstrated the occurrence of sexual conjugation in the group; and the Coccidian life-history is now one of the best known among Sporozoa.

Coccidia appear to be confined[1] to four great phyla, Vertebrates,

  1. A curious organism, parasitic in a gregarine, has lately been described by Dogiel as a coccidian, and termed Hyalosphaera.