242 GLOSSARY. 



Asbestos, a fibrous incombustible mineral. 



Analysis, separating the elements of a compound. 



Azure, sky blue. 



Alluvium, the sediment of rivers such as sand, vegetable mat- 

 ter, mud, &c. 



Augite, a simple mineral of a dark green or black color, found 

 as a constituent in many volcanic rocks. 



Amygdaloid, one of the trap rocks through which are scatter- 

 ed agates and simple minerals. 



Agate, a translucent silicious mineral of many varieties. 



Apocrenic acid, an acid found in peat and humus soils. 



Atmosphere, the air which we breathe. 



Aggregate, the sum of several particulars. 



Anhydrous, destitute of water. 



Aurora Borealis, Northern Lights. 



Aqueous, wateiy. 



Aerolite, a meteoric stone falling through the air. 



Alternate, leaves growing on opposite sides of the stem at dif- 

 ferent distances, but not opposite each other, are alternate. 



Alburnum, sap-wood. 



Accretion, increasing in size by the addition of new matter. 



Alchemy, the pretended science from which chemistry origina- 

 ted : its operations consisted in trying to change the baser 

 metals into gold ; to find a universal solvent and a remedy 

 for all diseases. 



Attenuation, the act of making fine, thin, minute. 



Angle of incidence, the angle at which a moving body strikes 

 another. 



Angle of reflection, the angle at which a moving body leaves 

 or bounds from another. 



Aquafortis, nitric acid. 



Aqua-ammonia, spirit of hartshorn. 



Acrid, sharp, pungent, biting. 



Acid, sour, having chemical properties opposite to alkalies. 



