OF CENTRAL CANADA PART I. 47 



whilst the emission of copious fumes, and deposition of a white coat- 

 ing on the charcoal, may be safely considered to indicate antimony. 

 The coating or sublimate formed by Zinc (see below), although white 

 when cold, is lemon-yellow whilst hot. Bismuth compounds if fused 

 in powder with a mixture of sulphur and iodide of potassium produce 

 on charcoal a vivid scarlet incrustation (Yon Kobell). If metallic 

 tin and lead, in about equal proportions, be fused together, the re- 

 sulting globule immediately oxidises, and on removal from the flame 

 continues to push out white and yellow excrescences (Chapman's Blow- 

 pipe Practice, p. 92). 



SECTION 2. REDUCIBLE : BUT YIELDING NO METAL ON CHARCOAL. 



(This arises from the rapid volatilization of the reduced metal.) 



Group 1. Volatilizing without odour, and without formation of 

 deposit on the charcoal. 



Mercury. 



For the proper detection of this metal, a small portion of the test- 

 substance in powder must be mixed with some previously dried carb. 

 soda, and the mixture strongly ignited at the bottom of a small tube 

 or narrow flask. If mercury be present, a grey sublimate will be 

 formed. By friction with a wire, &c., this runs into small metallic 

 globules which may be poured out of the tube. 



Group 2. Volatilizing without odour, but forming a deposit on the 

 charcoal. 



Cadmium. Zinc t 



The deposit produced by cadmium is dark brown or reddish-brown. 

 That produced by zinc is lemon-yellow and phosphorescent whilst 

 hot, and white when cold. If moistened with a drop of nitrate of 

 cobalt and ignited, it becomes bright green. 



Group 3. Volatilizing with strong odour of garlic. 



Arsenic. 



See additional reaction under Operation 4, page 32, above. 



SECTION 3. NOT REDUCIBLE BEFORE THE BLOWPIPE. 



Group 1. Imparting a colour to borax. 



Manganese. Chromium. 



Manganese compounds impart, before an oxidating flame, a violet 

 colour to borax ; Chromium compounds, a clear green colour. See 

 also under " Carbonate of Soda " page 36, above. 



