550 Transactions of th Society. 



the fragment of paper being dried and ignited carefully iu a 

 platinum dish, or upon foil of that metal. When the paper is 

 reduced to white ash, if the particle be metallic it will appear as a 

 black speck iu the ash. The latter is then placed upoo ;i glass 

 slip, a drop of dilute hydrochloric acid added, and warmed. To 

 this is added, when cold, a drop of starch solution containing 

 potassium iodide. If cupper be present, an intense blue or black 

 coloration results ; iron gives the same reaction, but, in the absenn- 

 of iron, copper is indicated, these two metals being the only ones 

 found, as a rule, in paper. 



