364 Account of some new Experiments 



was become perfectly black, and that the glass jar was 

 yellowish, and its transparency diminished. 



On weighing the shavings, which retained their origi- 

 nal figure completely, I was surprised to find that they 

 weighed only 2.21 grammes. As they were the remains 

 of 5 grammes of wood, 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, I did 

 not think it possible to reduce the weight of the shav- 

 ings to less" than 2.5 grammes, particularly with the 

 moderate heat I employed. 



To clear up my doubts, I replaced the apparatus 

 in the stove, and heated it again as before for twelve 

 hours, and afterwards left it in the stove twelve hours 

 to cool. 



On taking out the apparatus, I found that the shav- 

 ings weighed only 1.5 grammes. The jar was less trans- 

 parent, and of a blackish-yellow colour throughout, but 

 particularly in its upper part, above the level of the 

 brim of the saucer in which the shavings were. These 

 shavings were still of a perfect black. 



Having heated the apparatus again for twelve hours, 

 and then left it to cool, I was surprised, on taking it out 

 of the stove the next day, to find that the jar had again 

 become clear and transparent. Not the least trace of 

 the yellow coating with which its inner surface had been 

 covered now remained. 



On examining the wood, I found that this also had 

 changed its colour. It had assumed a bluish hue, 

 pretty deep, but very different from the decided black it 

 had before. Its weight was 1.02 grammes. 



I put it twice more into the stove, and each time its 

 weight was diminished, so that the 5 grammes of wood 



