222 V. SIMPLE COMBUSTIBLES.— 



woods is used for fuel, or for a support for substances exposed 

 to the flame of a blowpipe. Charcoal of animal substances has 

 the greatest clarifying power. Charcoal made by a low red heat, 

 not exceeding cherry red, has a dull surface, and is best for 

 clarifying liquids, and probably for making gunpowder, or for 

 fuel. If the heat is carried beyond this point, the charcoal acquires 

 a brilliant surface, and is considerably inferior for clarifying, and, 

 probably, for every other use. 



Oak charcoal. Beech Jcharcoal, Hazel charcoaL Pile-burned 

 are those commonly sold in London for fuel. 



Willow chaucoal, Carho ligni. Pile-burned is sometimes 

 found mixed with the common charcoal, and picked out for 

 crayons, to polish copper plates, tooth powder, and to put into 

 poultices to correct fetid ulcers ; also as an alterative in chronic 

 costiveness. 



Alder charcoal ; — Dog-wood charcoal ; — Spindle-wood char- 

 coal. Distilled in iron cylinders for making gunpowder : they 

 must not be allowed to absorb the vapour contained in the receiv- 

 ing-vessels. 



Chestnut charcoal. Bums slowly, and if blown, deadens 

 immediately upon the blast being stopped ; used by smiths for 

 forging. 



Areca nut charcoal. Vaunted as a dentifrice; willow 

 charcoal is sold for it. 



Charcoal dust. The dust collected from the scuttles, used 

 to reduce metallic oxides and similar purposes. 



Vegetable charcoal, Charhon vegetable. Charcoal dust 

 ground with water ; used to clarify liquids. 



Beech black. Blue black. Beech wood burned in close 

 vessels ; ground with white lead and oil produces a bluish-grey 

 colour ; used as paint. 



Frankfort black. Made of the lees of wine, or argol, well 

 washed and ground with water : used to make printers' ink. 



NoiR d'Espagne, Suber ustum. Made of cork burnt in close 

 vessels ; used as a colour in painting. 



Peach-stone black. Peach stones, and the nuts of other 

 stone fruits, as cherries, burnt in close vessels ; ground with white 

 lead and oil it produces the colour called old gray. 



Vine-twig black. Vine twigs burnt in close vessels ; bluish- 

 black ; ground, mixed with white lead and oil, it produces a silver 

 white colour. 



Rice black. From burnt rice ; is deficient in colour. 



