No. 129] 197 



These all throw out heat in proportion to the quantity of carbon 

 they contain. The dry woods yield a far greater proportion of 

 heat than the wet woods ; they contain one tliird of their weight 

 in water. One. pint of water in a stick of unseasoned wood 

 placed on a tire, forms seventeea hundred pints of vapor, which 

 carries the heat expended in its formation up the flue. Recently 

 «ut wood contains from 30 to 50 per cent of water, for example, 

 fir holds 44 per cent, pine 40 per cent, beech 39 per cent, birch 

 29, oak 36, and even Avhen dry, most WTjod contains 9 or 10 per 

 -cent of moisture. Trees that have matured themselves without 

 showing signs of decay, say that have reached 120 yeai^s, are 

 much better than trees sixty years old for fuel, decaying trees 

 are of little value for burning, any wood burned in a close stove 

 will give one third more heat, than that burned in an open fire 

 place, for the reason that in an open fire place the heat radiates, 

 and is dissipated by coming in contact v.'ith the atmospheiic in- 

 fluence j wjiich cannot be the case in a close stove, where it can 

 be perfectly managed with a proper damper. 



Charcoal from possessing singular properties, is very valuable 

 as fuel ; it is the carbon of wood, or that which is left after the 

 hydrogfn or oxygen are driven off by burning; the carbon not 

 being so combast ble as hydrogen requires more atmospheric air 

 to ignite it; this not being allowed by the manufacturer, it re- 

 mains in its original position, and contains, in one inch square, 

 nearly six million of pores. When used as fuel, atmospheric air 

 is freely admitted, it burns readily and gives out a great deal of 

 keat; forming carbonic acid gas, which soon fills small, badly 

 ventilated apartments, causing death by suffocation to those ex- 

 posed to its pernicious qualities. The ashes contain lime, silex, 

 potash. &c., all of which are valuable adjuncts to the agricultu- 

 rist. Flame is not emitted by burning charcoal, from the fact 

 tliat the hydrogen was dissipated by the first burning; and it is 

 th^t which causes flame from the combustion of wood. The dia- 

 mond is supposed to be crystallized carbon. It is not known 

 whether black is the natural color of the element, carbon, or not. 

 The best charc( al for commercial purposes is made of soft wood, 

 such as willow, &,c., which is used for the manufacture of gun 

 powdtr, crayons and polishing, but for fuel the hard wood charr 



