166 METTALLOIDS. 



already been shown, will burn, in chlorine gas, even 

 without kindling. 



Mention some 373. COMPOUNDS OF CHLORINE AND OXY- 



compounds of GEN Chlorine combines with five atoms 



chlorine and 



oxygen- of oxygen to form chloric acid. This acid 



is of importance, principally, as a constituent of the 

 chlorate of potash, to be hereafter mentioned in con- 

 nection with Nitrates. Hypoclorous acid a constitu- 

 ent of bleaching powders is another compound of chlo- 

 rine with oxygen. It is again mentioned in the section 

 on Chlorides. 



IODINE. 



v/ 

 374. DESCRIPTION. Iodine is commonly 



dine? WJiere seen in the form of brilliant blue-black 

 is it found? scales, somewhat similar to plumbago in 

 appearance. In odor it resembles chlorine. It is found 

 in the water of the ocean, in sea-weeds, sponges, &c., 

 but always in combination with sodium, or some 

 other metal. Minute traces of it are found to exist in 

 the atmosphere, and thence are transferred to the bodies 

 of animals. 



375. PREPARATION. For the preparation 



Explain the . . 



manufacture oi iodine, a lye 



of iodine? made fj . om the 



ashes of certain sea-weeds, 

 is heated with oil of vitriol 

 and black oxide of manga- 

 nese. The liberated oxy- 

 gen of the latter expels va- 



