538 THE IMPROVED ART OF FARRIERY. 



out on a healed brass plate or dish. The calcination 

 of antimony, in order to procure transparent glass, 

 succeeds very slowly, unless the operator be wary 

 and circumspect in the management of it. 



The most convenient vessel is a broad shallow dish, 

 or smooth flat tile, placed under a chimney. The an- 

 timony should be the purer sort, such as is usually 

 found at the apex of the canes ; this, grossly pow- 

 dered, is to be evenly spread over the bottom of the 

 pan, so as not to lie above a quarter of an inch thick 

 upon any part. 



The fire should be at first, no greater than is just 

 sufficient to raise a fume from the antimony, which is 

 to be now and then stirred ; when the fumes begin to 

 decay, increase the heat, taking care not to raise it so 

 high as to melt the antimony, or to run the powder 

 into lumps. After some time, the vessel maybe made 

 red-hot, and kept in that state, until the matter will 

 not, on being stirred, any longer fume. If this part 

 of the process be duly conducted, the antimony will 

 appear in an uniform powder, without any lumps, and 

 of a grey colour. 



With this powder, fill two-thirds of a crucible, which 

 is to be covered with a tile, and placed in a wind fur- 

 nace. Gradually increase the heat until the calx be 

 in perfect fusion, when it is to be occasionally ex- 

 amined by dipping a clean iron wire in it. If the 

 matter which adheres to the end of the wire appears 

 smooth and equally transparent, the vitrification is 

 completed, and the glass may be poured out on a hot 

 smooth stone or copper plate, and suffered to cool 

 slowly, to prevent its cracking and flying in pieces 

 It is of a transparent yellowish red colour. 



