WOOD, 



well known, a quantity of charcoal behind. The following 

 is the proportion yielded by one hundred parts of different 

 woods, according to the experiments of Prouft : 



Black a(h 

 Guaiacum 

 Pine 



Green oak 

 Heart of oak 

 Wild afh 

 White afh 



25 



24 

 20 

 20 

 19 

 17 

 17 



Poplar 



Lime 



Fir - 



Maple 



Elm 



Oak 



43-57 



43-59 

 44.18 

 42.23 



43-27 

 43.00 



Count Rumford, by continuing a very moderate fire for 

 ninety-fix hours, procured much larger proportions of char- 

 coal from different woods than were obtained in the above 

 experiments of Prouft. According to this chemift, one hun- 

 dred parts of different wood yielded, 



The woody fibre, when completely burnt, always leaves a 

 certain proportion of earthy and faline matters, which con- 

 flitute the ajlies of wood. Different woods yield very dif- 

 ferent proportions of afhes. See Ashes and Charcoal, where 

 other experiments by Mr. Mufhet on this fubjeft are related. 



The following Table exhibits the quantity of afhes left 

 by different woods, according to Sauffiire junior. SauiFure 

 has extended the invefligation to herbaceous and other 

 plants ; but we have omitted thefe, from their not being im- 

 mediately connefted with the prefent fubjeft. See Carbon. 



See Dr. Thomfon's Syftem of Chemiflry, vol. iv. 5th edit. 



Wood, On making Bread from. Profeflbr Autenrieth, 

 of Tubingen, has lately attempted to make bread from 

 wood, and his experiments feem to have been attended with 

 confiderable fuccefs. He had been led to form the opinion 

 that the woody fibre was only rendered unfit for food from 

 the foreign fubftances ufually attached to it, and from its 

 compaft aggregation. The firfl of thefe difficulties he 

 attempted to obviate, by fele£ting thofe woods which have 

 little tafle and fmell, and which confequently contain lefs 

 foreign matters ; fuch, for example, are the birch and beech, 

 efpecially the birch, which was the wood he chiefly employed 

 in his experiments. 



To render wood alimentary, it is necefTary to reduce it to 

 a ftate of extremely minute divifion, or abfolute powder. 

 It alfo requires the repeated aftion of the heat of an oven, 

 by which means it is not only better fitted for being ground, 

 but probably alfo undergoes fome internal change which 

 renders it more digeftible, as is evidently the cafe in regard 

 to coffee. Wood prepared in this way acquires the fmell 

 and tafte of corn-flour. It is, however, never white, but 

 always yellowifh. It alfo agrees with corn-flour in requir- 

 ing the addition of fome leaven, to enable it to undergo the 



fermentative procefs, and the four leaven of corn-flour is 

 found to anfvver the beft. With this it makes a perfeftly 

 uniform and fpongy bread, like common brown bread ; and 

 when it is thoroughly baked, and has much cruft, it has a 

 much better tafle of bread than what in times of fcarcity is 

 prepared of bran and huflcs of corn. 



To make wood-flour in perfeAion, the wood, after being 

 thoroughly flripped of its bark, is to be fawed tranfverfeiy 

 into diiks of about an inch in diameter. The faw-dufl is to 

 be preferved, and the difl<s to be beaten to fibres in a pound- 

 ing-mill. The fibres and faw-dufl mixed together are next 

 to be deprived of every thing harih and bitter, and which is 

 foluble in water, by boiling them in a large quantity of water 

 when fuel is abundant, or by fubjedling them for a longer 

 time to the aftion of cold water, as by placinij thtrni in a 

 rivulet, for example, enclofed in a fack. The whole is 

 then to be completely dried, either by the fun or fire, and 

 repeatedly ground in a flour-mill till it pafs through the 

 boulting-cloth. 



The ground wood is next to be baked into imall fiat 

 cakes, with water rendered flightly m'xilaginous by the ad- 

 dition of fome decodlion of linfeed, or any other fimilar fub- 

 ftance. Profeffor Autenrieth prefers marfh-maUow roots, 



of 



