140 VOCABULARY OF 



Carburets, a combination of Carbon with a base. 



Catacouslics, the science of reflected sounds or echoes. See page 51. 



Catoptrics, the science of reflected vision. See page 28. 



Centre of Gravity, that point of a body about which all its various 



parts exactly balance each other. 



Cerium, a recently discovered metal of which little is known. 

 Chalcedony, a kind of quartz. 



Chromium, a newly discovered metal, white, brittle, and of low spe- 

 cific gravity ; it is noted for' the beautiful colour it gives to other 

 bodies when in combination with them. 

 Chlorine, a peculiar kind of suffocating gas. See page 77. 

 Chromatics, that part of Optics that explains the properties of the 



colour of bodies. 

 Chrysolite, a precious stone having the property of becoming electric 



when rubbed. 



Cinnalur, an ore of quicksilver. 

 Cobalt, a metal of a grey colour, and exceedingly brittle. It is used 



in pottery, and gives the beautiful blue colour to porcelain. 

 Cohesion, that kind of attraction that unites the particles of bodies. 



See page 13. 



Cold, the absence of heat, or atomic motion. See page 32. 

 Colour, a property inherent in light, depending on the different vibra- 

 tions excited in the optic nerves. See page 30. 

 Columbium, a metal discovered at the beginning of the present cen- 

 tury, and so called from the mineral from which it was first procured, 

 having been brought from America. It is of a dark colour, and par- 

 ticularly infusible ; it is of no real use. 

 Combustion, the decomposition of certain substances, attended with 



heat and fire. 



Conchology, the science which treats of shells. 



Condensation, the reducing of a body into less bulk or space. Con- 

 densation always produces heat. 



Copper, a well-known metal, very hard, sonorous, and elastic, and 

 nearly as malleable as gold. It has been found in various parts of 

 the world, but is most abundant in Cornwall, where as much as 

 10,000 tons per annum has been produced. Wales has also pro- 

 duced 2,000 tons per annum. It has a slight affinity for oxygen, 

 and will form chemical combinations with various substances. It 

 also forms a part of various alloys, of which brass, bell-metal, pinch- 

 beck, and the metal of which cannon is made, are the principal. 

 Crystal, a very hard and clear body, of which there are various kinds, 



presenting a resemblance to different precious stones. 

 Crystallization, an operation in which various earths, salts, &c., pass 



"from a fluid to a solid state. 

 Cyanogen, Prussic acid, a most virulent poison. 

 Decomposition, the reducing a body into its simple elements. 

 Decrepitation, the crackling noise that salts make when heated. 

 Deliquescence, a term applied to saline bodies becoming liquid through 



their affinity for the moisture of the atmosphere. 

 Dew, a kind of mist which falls when the sun is below the horizon. 

 See page 54. 



