quantity, or by the characteristic blue imparted to a bead
of borax or salt of phosphorus.On the large scale cobalt is produced chiefly as an accessory in the treatment of nickel ores. These consist chiefly of mixtures of small quantities of the purer minerals with pyrites, sulphuretted copper ores, or lead and silver ores, which require to be subjected to concentrating processes in order to get rid of the bulk of the iron, sulphur, and arsenic, aud produce a small amount of enriched regulus or metal, in which the more valuable metals are in combination with sulphur and arsenic. This is done by calcination, which drives off the sulphur and arsenic combined with the iron, the latter being oxidized and subsequently converted into slag by fusion with fluxes containing silica. Small quanti ties of cobalt, nickel, and copper ores, when associated with lead and silver ores, are in like manner gradually accumulated in a regulus by passing the regulus of the first fusion several times through the smelting furnace, whereby the lead and silver are in great part removed. The treatment of these purified and enriched products is conducted ou the large scale in a somewhat similar manner to a chemical analysis, in order to obtain both cobalt and nickel. The speiss, or regulus, is calcined and treated with strong hydrochloric acid to dissolve the oxides formed. By the addition of caustic lime, iron and arsenic are pre cipitated, and the clear liquid is treated with sulphuretted hydrogen so long as metallic sulphides are produced, the precipitate being allowed to settle. The solution then con taining only cobalt and nickel compounds, the former is separated by the addition of bleaching powder and caustic lime as sesquioxide, Co 2 O 3 , and the latter as hydrated oxide by a subsequent precipitation with lime.
In making smalts the purer arsenical ores are used. They are first calcined in a reverberatory or muffle furnace provided with chambers for condensing the arsenical fumes as completely as possible. The roasted ore, if it does not contain quartz, is mixed with a proportion of fine glass house sand and carbonate of potassium, but when it is sufficiently siliceous, as in the mixtures of cobalt ore and silica known as zaffre, only the alkaline carbonate is required. The fusion takes place in pots like those used in plate-glass making, aud requires about eight hours. The blue glass is led out into water till the pot is nearly empty, when a speiss containing the whole of the nickel of the ore is found at the bottom. The blue glass is then ground and levigated as already described.
The chief localities producing cobalt ores are Modum in Norway, Tunaberg in Sweden, Schneeberg in Saxony, Musen in Rhenish Prussia, and Mine Lamotte in Missouri ; a con siderable amount has also been obtained from Bolivia. In the Transvaal in South Africa a very pure variety of speiss cobalt free from nickel has been recently discovered. Smaller quantities of speiss or regulus are obtained from the smelting of silver and lead ores, at Freiberg, in the Harz, in Bohemia, and elsewhere.
(h. b.)
COBÁN, or Santo Domingo Cobán, a city of Central America, in the republic of Guatemala, and the department of Vera Paz, situated about 90 miles north of the city of Guatemala, on the direct route to Flores, not far from the source of the Rio de Cajabon, which flows into the Golfo Dolce. It occupies the slopes of a rounded hill, on the top of which is the central square or plaza, with the cathedral aud the ruins of the once magnificent Dominican monastery on the one side, and on the others the shops and houses of the merchants and artizans. The houses of Coban are low and covered with tiles ; and, as each with its garden and croft attached is curtained by a dense and lofty hedge, the streets have rather the appearance of woodland avenues. The cathedral is a large and imposing edifice, decorated in the interior with a barbaric profusion of ornament ; but like the rest of the public buildings of the town it shows signs of decay. Since the removal of the seat of the Pro vincial Government to Salama, the prosperity of Coban has greatly declined, but it still contains about 12,000 inhabitautSjWho carry on the weaving of cotton cloth, the cultivation of coffee, sugar, and pimento, and a considerable trade with the neighbouring provinces. The Spanish and Ladino part of the population does not exceed 2000 ; and the rest are Indians originally from the mountains of Chichen and Jucamel, who still speak the Kacchi or Quecchi language. Coban owes its origin to the missionary labours of the Dominicans of the 16th century, and more especially to Fray Pedro de Augulo, whose portrait is pre served in the cathedral. It was made the political capital of the province of Vera Paz, and obtained the arms of a city of the first rank.
COBBETT, William (1766-1835), one of the most vigorous of English political writers, was born near Farn- ham in Surrey, according to his own statement, on the 9th March 1766. He was the grandson of a farm-labourer, and the son of a small farmer ; and during his early life he worked on his father s farm. At the age of sixteen, inspired with patriotic feeling by the sight of the men-of- war in Portsmouth harbour, he offered himself as a sailor ; and at seventeen (May 1783) having, while on his way to Guildford fair, met the London coach, he suddenly resolved to accompany it to its destination. He arrived at Ludgate Hill with exactly half-a-crown in his pocket, but an old gentleman who had travelled with him invited him to his house, and obtained for him the situation of copying clerk in an attorney s office. He greatly disliked his new occupa tion; and rejecting all his father s entreaties that he would return home, he went down to Chatham early in 1784 with the intention of joining the marines. By some mis take, however, he was enlisted in a regiment of the line, which rather more than a year after proceeded to Sfc John s, New Brunswick. All his leisure time during the months he remained at Chatham was devoted to reading the contents of the circulating library of the town, and getting up by heart Lowth s English Grammar. His uniform good conduct, and the power of writing correctly which he had acquired, quickly raised him to the rank of corporal, from which, without passing through the intermediate grade of sergeant, he was promoted to that of sergeant-major. In November 1791 he was discharged at his own request, and received the official thanks of the major and the general who signed his discharge. But Cobbett s connection with the regiment did not end in this agreeable manner. He brought a serious charge against some of its officers, and instead of appearing at the trial fled to France (March 1792). The inquiry which was held in his absence resulted in a complete acquittal of the accused.
daughter of a sergeant-major of artillery ; he had met hex- some years before in New Brunswick, and had proved her to be endowed with energy and self-control equal to his own. In September of the same year (1792) he crossed to the United States, and for a time supported himself at Wilmington by teaching English to French emigrants. Among these was Talleyrand, who employed him, according to Cobbett s story, not because he was ignorant of English, but because he wished to purchase his pen, Cobbett made his first literary sensation by his Observations on the Emi gration of a Martyr to the Cause of Liberty, a clever retort on Dr Priestley, who had just landed in America complaining of the treatment he had received in England. This pamphlet was followed by a number of papers, signed " Peter Porcupine," and entitled Prospect from the, Congress Gallery, the Political Censor, and the Porcupine s Gazette.
In the spring of 1796, having quarrelled with his publisher,