WHEEI.ER & LUEDEKING IODINE IN BLOVVPIPING. 679 



of being a reagent that is easily and cheaply prepared, and does 

 not decompose on standing like the hydriodic acid. It is made 

 by simply dissolving the iodine in alcohol to saturation. 



Later, Mr. P. Cassamajor (Chem. News, 52, 1-2) showed that 

 silver iodide, when properly manipulated, will also reproduce the 

 iodide coats. While this is a further step in advance, in that it 

 substitutes a solid for a liquid reagent, which is so very desirable 

 in blowpiping, it requires careful manipulation, and is rather an 

 expensive reagent. 



Further investigation by the writers has shown that the simple 

 dry iodine scales, as ordinarily found in the market, will give 

 these reactions quite perfectly if the metals are present as sul- 

 phides, while, if we first mix the other compounds of the metals 

 with flowers of sulphur and then add the iodine scales, we are 

 able to bring out the reactions under all circumstances. 



It suggested itself that a simple fusion be made of this mixture 

 of sulphur and iodine, thus obtaining the two elements thoroughly 

 intermixed in their proper proportions. Thus a brown mass re- 

 sults of iodide of sulphur, which, when powdered, does not 

 volatilize or decompose on exposure, while it is now in very 

 convenient form for immediate use. 



The proportion found to be best adapted for general applica- 

 tion was 40 per cent, of iodine and 60 per cent, of sulphur. This 

 iodide of sulphur is mixed iu excess with the substance to be ex- 

 amined and then treated on one end of the tablet with the oxidiz- 

 ing flame, when the same results are obtained as before. This 

 simple solid iodide of sulphur gives the reactions with the same 

 clearness and delicacy as the hydriodic acid. It was by the use 

 of the iodide of sulphur that the original tablets were made 

 from which the plates 11, 12, 13. herewith appended, were 

 prepared. 



On referring to plate 11, the mercury coat as shown is the 

 result of standing several minutes ; when fresh, as first obtained, 

 the outer coat is yellow, but changes to red on standing. 



On plate 12 is shown the bismuth coat before and after treat- 

 ment with ammonia vapor. The lead coat on plate 1 2 is, per- 

 haps, more generally a simple yellow than the reddish-yellow as 

 represented. 



