CLASS III. 



Metallic Substances. 



AERATED IRON, 



Iron combined with Jixed Air. 



Synonymous Names. 

 ^Aperient farYron of mars. 



AERATED j 

 IRON. 1 



J Martial mephite. 



(^Carbonate of iron. 



Both iron and fixed air being found in aU 

 mod every fituation, and readily uniting toge- 

 ther, and, efpecially where the fixed air is in 

 any quantity, readily diffolving in water; it is no 

 wonder that this is among the moft common fub- 

 ftances met with in fprings. Waters containing 

 it are called chalybeate, or ferruginous waters; 

 and, from their ftrengthening medicinal quali- 

 ties, are very generally ufed. They have fome- 

 what of a ftyptic or irony tafte, mixed with fome 

 pungency, from the fuperabundant fixed air they 

 contain. . 



This water is very eafily known. 



A. a. In being expofed to the air, or heated, 

 it precipitates a brown powder, which is calx of 

 iron. The fixed air being decompofed; the water 

 will have a rainbow-coloured peiikie on it. 



(Ob. 



