On the Gas Blowpipe. 'i'dl 



Clark, page 58. " Fuses readily, and undergoes a partial com- 

 bustion and volatilization with loss of colour and of weight. One 

 of the solid angles of an octahedral crystal was entirely burned off 

 and volatilized in one of these experiments." 



Experiments on Silex, Alnmine, Barytes. 



Hare, page 304. " By exposure to the gaseous flame either on 

 supports of silver or of carbon, barytes, aluininc, and silex were 

 completely fused. The products of the fusion of alumine and silex 

 were substances very similar to each other and much resembling 

 white enamel." 



Silliman, page 101). "Silex: being in a fine powder it was 

 blown away by the current of gas, but when moistened with water 

 it becomes agglutinated by the heat, and vvas then perfectly fused 

 into a colourless glass." 



Clark, page .59. " Pure precipitated silica (peroxide of sili- 

 cium) becomes instantly fused into an orange coloured transpa- 

 rent glass. The colour may be due either to the charcoal serving 

 as a support, or, to the carbon of the oil used for making it into 

 a paste." 



On the Reduction of the Earths to the metallic State. 



Hare, page 394. " The result of the fusion of barytes was a 

 substance of an ash-coloured cast, which after long exposure 

 sometimes exhibited brilliant yellow specks. If it be certain that 

 barytes is an earth, these specks must have been discoloured 

 particles of the silver support, or of the pipes from which the 

 flame issued." 



Silliman, page 1 13. " During the action of the compound 

 flame upon alkaline earths, provided they were supported by 

 charcoal ; distinct globules rolled and darted out from the ignited 

 mass, and burned sometimes vividly and with peculiarly coloured 

 flame. From the nature of the experiments it will not be easy 

 to prove that these globules were the basis of the earths, and yet 

 there is the strongest reason to believe it. Circumstances could 

 scarcely be devised more favourable to the simultaneous fusion and 

 decomposition of these bodies: charcoal higiily ignited for a suj)- 

 port, and an atmosphere of hydrogen also in vivid and intense ig- 

 nition. That the oxygen should be under these circumstances 

 detached is not surprising ; but the high degree of heat and the 

 presence of oxygen necessarily burn up the metalloids almost as 

 soon as produced. If means could be devised to obviate this dif- 

 ficulty, the !)lowpii)eof Mr. Hare might become an important in- 

 strument of analytical research. We can scarcely fail to attribute 

 some of the appearances during the fusion of tlie leucite to the 

 decomposition of the potash it contains. This impression was 

 much strengthened by exposing potash and soda to the compound 



Vol.rj". No.277.iV%18liI. Uu flame 



