8 HAANBL ON BLOWPIPE EEACTIONS. 



Antimony gives a purplish-black not very volatile coating, which is not affected either 

 by ammonia or ammonium sulphide. This reaction i.s very sensitive and very satisfactory, 

 and may serve to differentiate between the iodide coatings of arsenic and antimony. The 

 reaction is equally satisfactory with the solid hydrate of the tetrachloride of tin. When 

 the hydrate is employed, it is advantageous to place a small lump of the reagent, not upon 

 the assay, but on the side of the assay nearest the flame, and to cause the O. F. to sweep 

 over both, so that the fumes of the reagent may pass over the heated assay. 



Molybdenum gives a greenish-blue coating, not to be confounded with the antimony 

 coatin"-. The coating is valueless for analytical purposes, since its production is very 

 uncertain. It is mentioned to prevent its being mistaken for the antimony-coating in case 

 it should make its appearance. 



