COR 



COL 



an accurate balance, and those that prove 

 too light are re-melted ; but those that 

 are too heavy are filed to the standard 

 weight. When the blanks are adjusted, 

 they are carried to the blanching-house, 

 where the blanks are brought to their 

 proper colour. They are next milled, 

 by means of a machine which consists of 

 two plates of steel in form of rulers, on 

 which the edging is engraved, half on the 

 one and half on the other. Being thus 

 edged, the impression is given them by 

 the mill, which is so contrived, that the 

 metal receives at once un impression on 

 each side, and becomes money as soon 

 as it has been examined and weighed. 

 The process for coining medals is nearly 

 the same with that of money : there is, 

 however, this difference, that money, 

 from the smallness of the relievo, re- 

 ceives its impression at once, whereas 

 medals require several strokes. The 

 figures of the coining-mill have been so 

 frequently given, that it seemed to us 

 needless to insert them here, especially 

 as a new method of coining has been in- 

 troduced by Messrs. Bolton and Watt, 

 which is shortly to be the only mode used 

 in this country. For this purpose build- 

 ings are erecting on Tower-Hill. This 

 machinery, invented by these able me- 

 chanicians, has been long used in the 

 manufacture of copper money; it works 

 the screw-presses for cutting out the 

 circular pieces of copper, and coins 

 both the edges and faces of the money 

 at the same time, with such superior ex- 

 cellence and cheapness of workmanship 

 as will prevent clandestine imitation. 

 By this machinery, four boys are capable 

 of striking 30,000 pieces of money in an 

 hour ; and the machine acts at the 

 same time as a register, and keeps an un- 

 erring account of the number of pieces 

 struck. 



COINING, in the tin-works, is the 

 weighing and stamping the blocks of 

 tin with a lion rampant, performed by 

 the king's officer; the duty for every 

 hundred weight being four shillings. 



COIX, in botany, a genus of the Mo- 

 noecia Triandria class and order. Na- 

 tural order of grasses. Essential charac- 

 ter : males in remote spikes ; calyx glume 

 two-flowered, awnless ; corolla glume 

 awnless; female, calyx glume two-flow- 

 ered ; corolla glume awnless ; style two- 

 parted ; seeds covered by the calyx ossi- 

 fied. There are three species. 



COKE, a preparation of fossil coal, 

 whereby it is deprived of the naphtha, 



bitumen, or asphaltum, it may contain, so 

 that, when applied to ce^:in purposes, 

 it may not communicate a bad flavour or 

 bad qualities. Coke is made in very 

 large ovens, principally from the refuse 

 or brush-coal, with which some pits 

 abound ; the coal in them being extreme- 

 ly brittle, and rarely coming away in 

 large pieces. The overs have vents and 

 mouths that are occasionally stopped, in 

 part, for the purpose of regulating the 

 heat, which in no case should be such 

 as to consume, but merely to char. The 

 ovens being closed at a proper time, 

 the fire is gradually extinguished, and 

 the coke is compacted into large masses, 

 requiring to be broken before they can 

 betaken out. In this state it will burn 

 with a clear and steady heat, free from 

 fumes, and consequently without occa- 

 sioning malt (which is usually dried with 

 coke, where coal pits are at hand) to 

 partake of a bituminous or smoky flavour. 

 Good coke should be light, rather little, 

 and more close than cellular ; that which 

 is of a deep ash colour is in general pre- 

 ferable: when black, or at all glossy, it 

 is a certain sign of the want of due pre- 

 paration : it ought to be equally char- 

 red, and in large lumps, from the size of 

 a quartern loaf to a bushel : the small 

 refuse is not profitable, and often is too 

 much burnt. 



COLCHICUM, in botany, meadow saf- 

 fron, a genus of the Hexandria Trigynia 

 class and order. Natural order of Spatha- 

 ceae. Junci, Jussieo. Essential charac- 

 ter: spathe ; corolla six-parted, with a 

 rooted tube ; capsule three, connected, 

 inflated. There are three species. One 

 of them, viz. C. autumnale, has been sup- 

 posed by Mr. Want to be the base of the 

 Eau medicinale d'Hussor. 



COLD. When we leave a room at 

 the temperature of 60, and go into the 

 air in a frosty day at the temperature of 

 30, we say it is cold; or when the hand 

 is held in water at the temperature of 

 100 for a few minutes, and then sudden- 

 ly plunged into water at the tempera- 

 ture of 40, the latter is said to be cold. 

 This, however, is merely an expression 

 of the sensation excited in the body, 

 which depends solely on the abstraction 

 of its heat. This may be proved by the 

 following experiment. If three quanti- 

 ties of water are taken, the first at the 

 temperature of 30, the second at the 

 temperature of 50, and the third at the 

 temperature of 98. Immerse the right 

 hand into the water at the temperature of 

 98, and the left into the water at the 



