VEGETABLE FIBRE, 149 



ly, giving out much smoke during combustion. Amongst 

 our mountains the peasants have no other method of light- 

 ing their dark dwellings, than by burning the wood of 

 resinous trees. 



The solubility of resin in alcohol occasions it to be used 

 as a basis in the spirit-of-wine varnishes : the dissolvent 

 evaporates as soon as the varnish is applied, and leaves a 

 coating of resin, which preserves the body from the action 

 of air or water, and at the same time gives to it a bril- 

 liancy, smoothness, and a beautiful color which may be 

 varied at pleasure. 



The smoke of resin condensed and collected in cham- 

 bers hung with linen or paper, forms the lamp-black which 

 is commonly employed in painting, stamping, printing, and 

 the composition of varnish. According to the experiments 

 of Messrs. Gay-Lussac and Thenard, 100 parts of common 

 resin contain 



Carbon 75.944 



Oxygen 13.337 



Hydrogen 10.719 



ARTICLE VII. 



Vegetable Fibre, 



Vegetable fibre is the frame-work of all the solid parts 

 of plants : it may be separated from vegetable substances 

 by the repeated action of water and alcohol, aided by 

 heat ; by maceration for a length of time ; or by distilla- 

 tion. By the first method the juices which are lodged in 

 the intervals of the fibres are dissolved ; by the second, 

 these juices are decomposed by fermentation ; by the third, 

 which is the least perfect, those principles which can be 

 volatilized by heat are driven off, but their carbon remains 

 united to that of the fibre, which is itself decomposed, though 

 preserving its form. 



Fibre separated from all other vegetable substances by 

 either of the two first-mentioned processes, is possessed of 

 a great degree of flexibility, is insoluble in water or alcohol, 

 and burns with a yellow flame. 



Art has succeeded in extracting the vegetable fibre from 

 13* 



