Page:EB1911 - Volume 12.djvu/676

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GUANIDINE—GUARANIS
651


Canaries (Paris, 1839); Paul Broca, Revue d’anthropologie, iv. (1874); General L. L. C. Faidherbe, Quelque mots sur l’ethnologie de l’archipel canarien (Paris, 1875); Chil y Naranjo, Estudios historicos, climatologicos y Patologicos de las Islas Canarias (Las Palmas, 1876–1889); “De la pluralité des races humaines de l’archipel canarien,” Bull. Soc. Anthrop. Paris, 1878; “Habitations et sépultures des anciens habitants des îles Canaries,” Revue d’anthrop., 1879; R. Verneau, “Sur les Sémites aux îles Canaries,” and “Sur les anciens habitants de la Isleta, Grande Canarie,” Bull. Soc. Anthrop. Paris, 1881; Rapport sur une mission scientifique dans l’archipel canarien (Paris, 1887); Cinq années de séjour aux îles Canaries (Paris, 1891); H. Meyer, Die Insel Tenerife (Leipzig, 1896), “Über die Urbewohner der canarischen Inseln,” in Adolf Bastian Festschrift (Berlin, 1896); F. von Luschan, Anhang über eine Schädelsammlung von den canarischen Inseln; R. Virchow, “Schädel mit Carionecrosis der Sagittalgegend,” Verhandlungen der Berliner Anthrop. Gesellschaft (1896); G. Sergi, The Mediterranean Race (London, 1901); The Guanches of Tenerife . . ., by Alonso de Espinosa, translated by Sir Clements Markham, with bibliography (Hakluyt Society, 1907).


GUANIDINE, CN3H5 or HN:C(NH2)2, the amidine of amidocarbonic acid. It occurs in beet juice. It was first prepared in 1861 by A. Strecker, who oxidized guanine with hydrochloric acid and potassium chlorate. It may be obtained synthetically by the action of ammonium iodide on cyanamide, CN·NH2 + NH4I = CN3H5·HI·; by heating ortho-carbonic esters with ammonia to 150° C.; but best by heating ammonium thiocyanate to 180°–190° C., when the thiourea first formed is converted into guanidine thiocyanate, 2CS(NH2)2 = HN:C(NH2)2·HCNS + H2S. It is a colourless crystalline solid, readily soluble in water and alcohol; it deliquesces on exposure to air. It has strong basic properties, absorbs carbon dioxide readily, and forms well-defined crystalline salts. Baryta water hydrolyses it to urea. By direct union with glycocoll acid, it yields glycocyamine, NH2·(HN):C·NH·CH2·CO2H, whilst with methyl glycocoll (sarcosine) it forms creatine, NH2·(NH):C·N(CH3)·CH2·CO2H.

Many derivatives of guanidine were obtained by J. Thiele (Ann., 1892, 270, p. 1; 1893, 273, p. 133; Ber., 1893, 26, pp. 2598, 2645). By the action of nitric acid on guanidine in the presence of sulphuric acid, nitroguanidine, HN:C(NH2)·NH·NO2 (a substance possessing acid properties) is obtained; from which, by reduction with zinc dust, amidoguanidine, HN:C(NH2)·NH·NH2, is formed. This amidoguanidine decomposes on hydrolysis with the formation of semicarbazide, NH2·CO·NH·NH2, which, in its turn, breaks down into carbon dioxide, ammonia and hydrazine. Amidoguanidine is a body of hydrazine type, for it reduces gold and silver salts and yields a benzylidine derivative. On oxidation with potassium permanganate, it gives azodicarbondiamidine nitrate, NH2·(HN):C·N:N·C:(NH)·NH2·2HNO3, which, when reduced by sulphuretted hydrogen, is converted into the corresponding hydrazodicarbondiamidine, NH2·(HN):C·NH·NH·C:(NH)·NH2. By the action of nitrous acid on a nitric acid solution of amidoguanidine, diazoguanidine nitrate, NH2·(HN):C·NH·N2·NO3, is obtained. This diazo compound is decomposed by caustic alkalis with the formation of cyanamide and hydrazoic acid, CH4N5·NO3 = N3H + CN·NH2 + HNO3, whilst acetates and carbonates convert it into amidotetrazotic acid, Amidotetrazotic acid yields addition compounds with amines, and by the further action of nitrous acid yields a very explosive derivative, diazotetrazol, CN6. By fusing guanidine with urea, dicyandiamidine H2N·(HN):C·NH·CO·NH2, is formed.


GUANO (a Spanish word from the Peruvian huanu, dung), the excrement of birds, found as large deposits on certain islands off the coast of Peru, and on others situated in the Southern ocean and off the west coast of Africa. The large proportions of phosphorus in the form of phosphates and of nitrogen as ammonium oxalate and urate renders it a valuable fertilizer. Bat’s guano, composed of the excrement of bats, is found in certain caves in New Zealand and elsewhere; it is similar in composition to Peruvian guano. (See Manures and Manuring.)


GUANTA, a port on the Caribbean coast of the state of Bermúdez, Venezuela, 12 m. N.E. of Barcelona, with which it is connected by rail. It dates from the completion of the railway to the coal mines of Naricual and Capiricual nearly 12 m. beyond Barcelona, and was created for the shipment of coal. The harbour is horseshoe-shaped, with its entrance, 1998 ft. wide, protected by an island less than 1 m. off the shore. The entrance is easy and safe, and the harbour affords secure anchorage for large vessels, with deep water alongside the iron railway wharf. These advantages have made Guanta the best port on this part of the coast, and the trade of Barcelona and that of a large inland district have been transferred to it. A prominent feature in its trade is the shipment of live cattle. Among its exports are sugar, coffee, cacáo, tobacco and fruit.


GUANTÁNAMO, the easternmost important town of the S. coast of Cuba, in the province of Santiago, about 40 m. E. of Santiago. Pop. (1907) 14,559. It is situated by the Guazo (or Guaso) river, on a little open plain between the mountains. The beautiful, land-locked harbour, 10 m. long from N. to S. and 4 m. wide in places, has an outer and an inner basin. The latter has a very narrow entrance, and 2 to 2·5 fathoms depth of water. From the port of Caimanera to the city of Guantánamo, 13 m. N., there is a railway, and the city has railway connexion with Santiago. Guantánamo is one of the two ports leased by Cuba to the United States for a naval station. It is the shipping-port and centre of a surrounding coffee-, sugar- and lime-growing district. In 1741 an English force under Admiral Edward Vernon and General Thomas Wentworth landed here to attack Santiago. They named the harbour Cumberland bay. After their retreat fortifications were begun. The history of the region practically dates, however, from the end of the 18th century, when it gained prosperity from the settlement of French refugees from Santo Domingo; the town, as such, dates only from 1822. Almost all the old families are of French descent, and French was the language locally most used as late as the last third of the 19th century. In recent years, especially since the Spanish-American War of 1898, the region has greatly changed socially and economically. Guantánamo was once a fashionable summer residence resort for wealthy Cubans.


GUARANA (so called from the Guaranis, an aboriginal American tribe), the plant Paullinia Cupana (or P. sorbilis) of the natural order Sapindaceae, indigenous to the north and west of Brazil. It has a smooth erect stem; large pinnate alternate leaves, composed of 5 oblong-oval leaflets; narrow panicles of short-stalked flowers; and ovoid or pyriform fruit about as large as a grape, and containing usually one seed only, which is shaped like a minute horse-chestnut. What is commonly known as guarana, guarana bread or Brazilian cocoa, is prepared from the seeds as follows. In October and November, at which time they become ripe, the seeds are removed from their capsules and sun-dried, so as to admit of the ready removal by hand of the white aril; they are next ground in a stone mortar or deep dish of hard sandstone; the powder, moistened by the addition of a small quantity of water, or by exposure to the dews, is then made into a paste with a certain proportion of whole or broken seeds, and worked up sometimes into balls, but usually into rolls not unlike German sausages, 5 to 8 in. in length, and 12 to 16 oz. in weight. After drying by artificial or solar heat, the guarana is packed between broad leaves in sacks or baskets. Thus prepared, it is of extreme hardness, and has a brown hue, a bitter astringent taste, and an odour faintly resembling that of roasted coffee. An inferior kind, softer and of a lighter colour, is manufactured by admixture of cocoa or cassava. Rasped or grated into sugar and water, guarana forms a beverage largely consumed in S. America. Its manufacture, originally confined to the Mauhés Indians, has spread into various parts of Brazil.

The properties of guarana as a nervous stimulant and restorative are due to the presence of what was originally described as a new principle and termed guaranine, but is now known to be identical with caffeine or theine. Besides this substance, which is stated to exist in it in the form of tannate, guarana yields on analysis the glucoside saponin, with tannin, starch, gum, three volatile oils, and an acrid green fixed oil (Fournier, Journ. de Pharm. vol. xxxix., 1861, p. 291).


GUARANIS, a tribe and stock of South American Indians, having their home in Paraguay, Uruguay and on the Brazilian coast. The Guaranis had developed some civilization before the arrival of the Spaniards, and being a peaceable people quickly submitted. They form to-day the chief element in the populations of Paraguay and Uruguay. Owing to its patronage by the Jesuit missionaries the Guarani language became a