COP 



COP 



from east to west, is imputed to the 

 Earth's motion from west to east, round 

 its axis. This system was received of old 

 by Philolaus, Aristarchus, and Pythago- 

 ras, from wiiich last it had the name of 

 the Pythagoric system : it was also held 

 by Archimedes ; but after him it became 

 neglected, and even forgotten for many 

 ages, till it was revived by Copernicus, 

 about the year 1500, and from him named 

 the Copernican system. According to 

 this hypothesis, the Sun is supposed very 

 nearly the centre of gravity of the whole 

 system, and in the common focus of every 

 one of the planetary orbits : next to him 

 Mercury performs his revolution around 

 him ; next Mercury is the orbit of Venus ; 

 then the Earth, with its attendant or se- 

 condary, the Moon, performing a joint 

 course, and in their revolution measur- 

 ing out the annual period. Next the 

 Earth is Mars, the first of the superior 

 planets; next him Jupiter, then Saturn, 

 and lastly, the Herschel planet. Be- 

 tween Mars and Jupiter have been dis- 

 covered four very small bodies, called 

 ASTEROIBES ; which see. 



These and the comets are the consti- 

 tuent parts of the solar system, which is 

 now received and approved as the only 

 true one. See ASTRONOMY. 



COPERNICUS (NICHOLAS) in biogra- 

 phy, was born at Thorn, in Prussia, in 

 1472. Having acquired, during the course 

 of his education at Cracow, a fondness 

 for mathematical studies, and particular- 

 ly for astronomy, he went to Bologna, to 

 prosecute these studies under an emi- 

 nent astronomer of that university. Here 

 he obtained such distinction, that he was 

 appointed professor of mathematics at 

 Borne. Returning after some years to 

 his native country, he obtained a canon- 

 ry in the cathedral church of Frauen- 

 burg, and in the leisure which this situa- 

 tion afforded him pursued his astrono- 

 mical speculations. Perceiving the Ptole- 

 maic system (which supposes the Earth 

 to be fixed in the centre, and the Moon, 

 Mercury, Venus, the Sun, Mars, Jupiter, 

 and Saturn, to revolve about it in con- 

 rentric circles) to be inconsistent with 

 the phenomena, and encumbered with 

 many absurdities, he had recourse to the 

 Pythagorean hypothesis, which places 

 the Sun in the centre of the system, and 

 makes the Earth a planet, revolving an- 

 nually with the rest about the Sun, and 

 daily about its own axis. Upon this sys- 

 tem, compared with the observations 

 which had been made by others and 

 himself, he proceeded to ascertain the 

 periodical revolutions of the planets, 



and wrote his treatise, " De Orbium 

 Coelestium Revolutionibus*' " On the 

 Revolutions of the Heavenly Bodies,** 

 in which he demonstrated them geome- 

 trically. 



A doctrine which explained the celes- 

 tial phenomena with so much simplicity 

 could not fail to engage the attention 

 and admiration of astronomers and phi- 

 losophers. But, on account of its in- 

 consistency with some passages of scrip- 

 ture, it was rejected by many divines, 

 and censured in an express decree of 

 the Romish Church. Nevertheless the 

 doctrine daily gained ground, and is now 

 universally received. Copernicus died 

 in 1543. 



COPPEL, COPEI, or CCPPEL, a chemi- 

 cal vessel made of earth, pretty thick, 

 and of the form of a platter or dish. See 

 LABORATORY. 



COPPER, in the arts, seems to have 

 been known in the remotest periods of 

 antiquity. It is among the first me- 

 tals which was employed by the early 

 nations of the world; it is not one of the 

 scarce metals, is easily extracted from its 

 ores, and not difficult to work. The 

 Egyptians applied it to a great variety of 

 uses, as it appears from die earliest pe- 

 riod of their history. The Greeks were 

 acquainted with the mode of working cop- 

 per, and employed it in many of the arts. 

 It was the basis of the celebrated Corin- 

 thian metal. The Romans knew the uses 

 of this metal, and it is generally supposed 

 that of it they fabricated the greatest 

 number of their utensils. The alloys 

 which they made with copper, after the 

 example of the Egyptians and Greeks, 

 were very numerous, and applied to a 

 great variety of uses. Copper exists in 

 considerable abundance in nature ; it is 

 found native, alloyed with other metals, 

 combined with sulphur, in the state of 

 oxide, and in that of salt. It is not un- 

 frequently met with in the native state, 

 sometimes crystallized in an arborescent 

 form, and sometimes in more regular 

 figures. Copper exists native, alloyed 

 with gold and silver. The most abundant 

 ores of copper are the sulphurets, and of 

 these there is a considerable variety, ex- 

 hibiting various colours and various forms 

 of crystals. In the state of oxide it has 

 been found in Peru, of a greenish colour, 

 mixed with white sand. In the state of 

 salt, copper is combined with the sulphu- 

 ric and carbonic acids, forming native sul- 

 phates and carbonates of copper. The 

 latter present many varieties, but may 

 chiefly be referred to the blue and green 



