Page:The American Cyclopædia (1879) Volume IV.djvu/660

 648 CLAVIERE CLAY the side of the chest. It also protects im- portant vessels lying behind it. Being im- mediately beneath the skin, it forms a sort of ridge, which is very marked in persons who are very thin. In the male the clavicles are more curved and robust than in the female. CLA EKKK, Kticiinc, a banker of GeMeva, born Jan. 27, 1735, died Dec. 8, 1793. Having es- tablished himself in Paris, he became acquaint- ed with Mirabeau, Brissot, and other leaders of the revolutionary party, and was appointed minister of finance in March, 1792. As an opponent of the extreme measures of Robes- pierre, he fell with the Girondists, being ar- rested June 2, 1793, and to escape the guillo- tine stabbed himself to death, His wife poi- soned herself two days afterward. He wrote on financial subjects. CLAYICERO, Frantisco Saverio, a Mexican his- torian, born in Vera Cruz about 1720, died at Cesena, Italy, in October, 1793. He spent 86 years in collecting historical materials in Mexi- co, and acquiring the native languages, living at times entirely among the Indians, noting their traditions, and examining historical paint- ings, manuscripts, and monuments. After the suppression by Spain of the order of Jesuits, of which he was a member (1767), he retired to Italy, and was with other Jesuits from Span- ish America assigned by the pope a residence at Cesena, where he wrote Storia antica del Mexico (4 vols. 4to, Cesena, l780-'83). The work evinces more research than judgment. Its great merit is its impartiality, especially in relating the story of the conquest by Cortes. An English translation of it by C. Culkn was published in 1787. CLAVIJO, Ray Gonzalez d, one of the ambas- sadors of Henry III. of Castile to Tamerlane, died in Madrid in 1412. He wrote a minute account of the whole embassy, its adventures and its results. It was first published in 1582 by Argote de Molina, an antiquary of the time of Philip II., under the title of Historia del gran Tamerlan, &c., though it contained only a diary of the ambassadors, beginning in May, 1403, when they embarked at Puerto Santa Maria, near Cadiz, and ending in March, 1406, when they landed there on their return. A new and excellent edition appeared in Madrid in 1782. This work contains interesting descriptions of Constantinople, Trebizond, Teheran, and of Sa- marcand, where the ambassadors were sump- tuously entertained by Tamerlane. Clavijo on his return to Madrid was received with distinc- tion by the king ; he was one of the witnesses of the king's will, and was buried in the con- vent of St. Francis. His life is to be found in vol. iv. of ffijos de Madrid, &c. (Madrid, 1789). CLAVIJO 1 FAXARDO, Jose, a Spanish author, born in the Canary islands about 1730, died in Madrid in 1806. He owes Ms notoriety mainly to his duel with Beaumarchais, who challenged him because Clavijo had broken his promise to marry one of his sisters to whom he had paid his addresses. By the influence of Beaumar- chais he lost the office of keeper of the ar- chives, which he had held in Madrid ; but a few years later he was appointed editor of the official paper, El Mercuric de Madrid, and also officiated for some time as director of a theatre. He furnished a Spanish translation of Buffon's " Natural History," for which he was rewarded by being appointed assistant director of the museum of natural history at Madrid. His adventure with Beaumarchais's sister has been dramatized by several poets, and most successfully by Goethe, who followed, however, the unfavorable sketch in the witty Frenchman's memoirs, while Clavijo is said to have been a worthy gentleman. CLAY, a finely levigated silico-aluminons earth, found in its natural state in beds of varying depth, and in lamina of varying thick- ness. It is formed by the disintegration of feldspathic rocks, and the precipitation in ba- sins from suspension in water of the finely di- vided, impalpable particles. It may be to a certain extent derived from slate rocks, and in such case is only the original clay from which the slate was formed, reproduced; but the original source was feldspathic or granite rock. The aluminous minerals contained in granite rocks are feldspar, mica, and hornblende. Ordinary granite is composed of quartz, feld- spar, and mica. In syenitic granite mica is partly or wholly replaced by hornblende. These minerals contain alumina in varying proportions, in combination with silica, form- ing silicate of alumina, and they also contain al- kaline silicates, either of potassium or sodium. Mica and hornblende generally contain con- siderable oxide of iron, while feldspar usually yields only traces, or none. Therefore, clays which are derived from feldspar are light-col- ored or white, while those partially made up of decomposed mica or hornblende are dark, either bluish or red. As a rule, however, feld- spar is the constituent of granite in fine clay, as the particles of the other minerals do not be- come so finely divided, and therefore are de- posited before reaching the basin where the fine clay is formed. Clay may be formed ar- tificially from certain decomposed granites which are found in various parts of the United States, particularly in the vicinity of Washing- ton, D. C. These beds are often found in a sufficiently soft condition to admit of being cut with the spade to the depth of 20 or 30 ft. A mass of the excavated rock is placed in a sluice and drenched with water, which is made to run into a tank. Here the coarser portions subside, while those more finely suspended run out with the water at the top into another tank, in which again there is another separa- tion made in a similar manner, the finest par- ticles passing into a third tank, where after a time they are precipitated. The water is then carefully drawn off, and the clay allowed to become sufficiently dry to be cut with a spado and removed. A fine white pipe clay may be procured in this manner. Clays have varying