C A 



[97] 



COB 



moment of our lives, a personal 

 concern in the geological events of 

 these very distant eras. We are 

 all brought into immediate con- 

 nexion with the vegetation that 

 clothed the ancient earth, before 

 one-half of its actual surface had 

 yet been formed. The trees of the 

 primeval forests have not, like 

 modern trees, undergone decay, 

 yielding back their elements to the 

 soil and atmosphere by which they 

 had been nourished ; but, treasured 

 up in subterranean storehouses, have 

 been transformed into enduring 

 beds of coal, which, in these later 

 ages, have become to man the 

 sources of heat, and light, and 

 wealth. My fire now burns with 

 fuel, and my lamp is shining with 

 the light of gas, derived from coal 

 which has been buried for countless 

 ages in the deep and dark recesses 

 of the earth. We prepare our 

 food, and maintain our forges and 

 furnaces, and the power of our 

 steam-engines, with the remains of 

 plants of ancient forms and extinct 

 species, which were swept from 

 the earth ere the formation of the 

 transition series was completed. 

 Thus, from the wreck of forests 

 that waved upon the surface of the 

 primeval lands, and from ferrugi- 

 nous mud that was lodged at the 

 bottom of the primeval waters, we 

 derive our chief supplies of coal 

 and iron ; those two fundamental 

 elements of art and industry, which 

 contribute more than any other 

 mineral production of the earth, to 

 increase the riches, and multiply 

 the comforts, and ameliorate the 

 condition of mankind. 

 COAL MEASURES. (The Terrain Ho- 

 uiller of the French, the Steinkoh- 

 lengebirge of the German geologists.) 

 The name given to one division of 

 the carboniferous group. The coal 

 measures consist of beds of coal, 

 sandstone, and shale, irregularly 

 interstratified, sometimes mixed 



with conglomerates. ' * The organic 

 remains discovered in the coal 

 measures are principally terrestrial 

 plants ; with these are a few fresh- 

 water shells, and certain marine 

 exuvia3, which, for the most part, 

 would rather appear to occur in 

 beds alternating with the coal beds 

 and their accompanying shales and 

 sandstones, than mingled with the 

 terrestrial remains." Thirty-five 

 genera and three hundred and ten 

 species of plants have been dis- 

 covered: ten genera and fourteen 

 species of conchifers : four genera 

 and fourteen species of mollusks: 

 and two genera and three species 

 of fishes. De la Beche. Manual 

 of Geology. 



COA'BCTATE. (coarctatus, Lat.) Press- 

 ed together. A term used in en- 

 tomology, to express that state 

 wherein the larva is. 



CO'BALT. (The word cobalt seems to 

 be derived from colalm, or kobold, 

 the name of a spirit, or goblin, 

 that, according to the superstitious 

 notions of the times, haunted mines, 

 destroyed the works of the miners, 

 and often gave them much un- 

 necessary trouble. It was once 

 customary in Germany to introduce 

 into the church service a prayer 

 that God would preserve miners 

 and their works from kobalts and 

 spirits.) 



This metal is of a gray colour, 

 with a shade of red, with but little 

 lustre ; its texture is fibrous ; spe- 

 cific gravity 8'6, or according to 

 some 7 '8. Fusible only at a 

 temperature of 16-677 of Fahren- 

 heit. When heated, cobalt is 

 partly malleable; it is permanently 

 magnetic. The fine blue mineral 

 called zaffre is an impure oxide of 

 this metal. The colour of this 

 oxide is so intense that a single 

 grain of it will impart a full blue 

 to 240 grains of glass. An oxide 

 of cobalt, dissolved in muriatic 

 acid, forms a sympathetic ink; 



