300 SALTS. 



a yellow ; chloride of potassium, violet ; 

 chloride of calcium, orange ; chloride of 

 barium, yellow ; chloride of copper, blue. 

 Instead of the chlorides, other soluble 

 salts may be employed with the addition of a little hy- 

 drochloric acid. , beautiful green may be obtained 

 from a copper coin moistened with strong nitric acid, 

 with the use of alcohol as before. The colors of fire- 

 works are similarly produced by the addition of the 

 above and certain other salts. 



754. OTHER CHLORIDES. The other 



What is said i i j / 



of other ckio- chlorides are not of sufficient general in- 

 terest to be here particularly described. Cor- 

 rosive sublimate, the uses of which are mentioned in 

 the chapter on Mercury, is a chloride of this metal. 

 Calomel is a subchloride of the same metal. 



IODIDES, BROMIDES AND FLUORIDES. 



755. The iodides and bromides are 



What is said 



of the iodides classes of salts analogous to the chlorides. 

 andbromides? Those o f potassium, used in medicine and 

 in photography, are the most important. 



756. DETECTION OF T <roioo<r IODINE. 

 JTowistheblue -r' i 1.1 i -, -, -,- 



iodide of A beautiful blue is prepared by adding a 

 pared r 6 ' little cnlorme water and starch paste to a 

 solution of iodide of potassium. The 

 chloride sets iodine at liberty, which then combines 

 with starch to form the blue compound. By this test 

 iodine can be detected in a liquid which contains but a 



