of fume Kbuh of Wood, 333 



powder by worms, burnt on an ignited plate of iron, were 

 completely incinerated, and left three parts of aftitte, which 

 is nearly the quantity obtained from a quintal of dry vine 

 twigs burnt with the greateft care. This wood, which ought 

 properly to be called worm-eaten, has nothing then in com- 

 mon with rotten wood called alfo worm-eaten, but the nam? 

 improperly applied to the latter. 



It has been faid, that rotten wood furniflies little faline 

 matter'*: this observation is correct in regard to wood 

 drenched by the rain ; the eighth experiment proves it ; but 

 it is proved by the third that wood which has rotted with- 

 out being drenched by rain, does not lofc an atom of its pot- 

 am, and that taking equal weights, as rotten wood furni flies 

 a double quantity of aflies equally rich, it will furnifh a 

 double quantity of faline matter. This affords a refource for 

 manufactories, efpecially when we confider the moderate 

 price of this wood, which in general is much neglected. 



The afhes of dead timber, the tops and bark of which 

 being well preferved have left no place of entrance for rain, 

 may be employed either in leys for domeftic purpofes, in 

 faltpetre manufactories, or fait works. The mould of thefe 

 trees will alfo form an excellent manure, fince it will have re- 

 tained all its potafh. It is thence ken, that where the mould 

 has been drenched with rain, vegetation has been benefitted. 

 We know by the experiments of Vauquelin, that the potalh 

 iu the fap of trees is in the (late of acetite : it would be highly- 

 gratifying to know in what (late it is in the wood and in the 

 mould. 1 



3d, The fourth experiment proves that the aflies by being 

 re-burnt lofea fifth of faline matter, and this rauft be the cafe 

 fince it diverts itfelf more and more of carbonic acid ; but 

 by thefe means it gains as much in quality as is proved in 

 particular by the eighth experiment. However, if very rich 

 aflies, fuch as that of the poplar, be re-burnt, a frit will be 

 obtained, or a femivitrification, which will retain a part of 

 the potafh : befides, this frit, in order to be lixiviated, mud 

 be triturated, which will increafe the labour. This frit, 

 from which may be extracted 30 per cent, of faline matter, 

 and which will then ftill contain a great deal of it, would per- 

 haps be as proper for glafs-making as certain kinds of foda. 



This femi-vitreous ftate, and tne firmnefs of the foaps ob- 

 tained in the eighth experiment, induced me at firfl to be- 



• -Annates de Cbimhy vol. xix. p. 160. The fame thing has been hid 

 of fdwduft, and carpenter's chips : this depends on the wood empioye J, 

 and the manner of cutting or dividing the wood, io a> not to change 

 thing in its nature. 



lieve, 



