ON WOOD AND CHARCOAL. 101 



On taking out the shavings the next day, they hail all Change of 

 changed colour more or less: from a yellowish white they coiour '> 

 had become light brown, dark brown, more or less yellow, 

 and some of a fine purple. 



Their weight, which was at first 10 grs. was now found Weight after 

 to be 



the second 

 heating, 



Oak 7-16 Cherry 8-60 



Elm 9*18 Linden 7*86 



Beech 8'59 — ■ (after ha- 



Maple 8*41 ving been in the 



Ash * • 8*40 open air twenty- 

 Birch 7-4Q four hours). •••8 , 06 



Service ...8*46 Male fir 8'46 



Female fir 8.66 



Wishing to know whether the wood might not be re- Attempt to 

 duced to charcoal by continuing the moderate heat of the £ ha ^ nJXr' / 1 

 stove a long time, 1 took half the linden shavings, which heat, 

 weighed 4*03 gr, ; placed them in a china saucer, sup* 

 ported by a cylindrical earthen vessel three inches in 

 diameter, and four inches high; put this on an earthen 

 plate, and covered it by a glass jar, six inches in diameter, 

 and eight inches high. On the earthen plate was a layer of 

 ashes, about an inch deep, serving to close the mouth of 

 the jar slightly. 



This little apparatus being placed in the stove, it was 

 heated a third time for twelve hours ; and then left twelve 

 hours without fire, to cool gradually. 



On taking out the apparatus \ found, that the wood was Results, 

 become perfectly black ; and that the glass jar was yellow- 

 ish, and its transparency diminished. 



On weighing the shavings, which retained their original Loss of weight, 

 figure completely, I was surprised to find, that they 

 weighed only 2*91 grs. A» they were the remains of 5^»r. 

 of wood j and as, from the experiments of Messrs Gay* 

 Lussac and Thenard, I had expected to find in this wood at 

 least fifty per cent of charcoal j I did not think it possible, 

 to reduce the weight of the shavings to less than 2*5 gr. t 

 particularly with the moderate heat I employed.. 



To 



