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is inferred that the quantity of oxygen in sulphur amounts to about 

 ten per cent., and hence the intense ignition that occurs in the union 

 of sulphur with potassium, and other metallic bodies, is traced to a 

 more probable source than their mere affinity for sulphur. 



The same analogies apply to phosphorus as to sulphur ; the same 

 mode of operating was adopted, and products perfectly analogous 

 were obtained. By electrization, phosphuretted hydrogen was given 

 out, and the phosphorus became of a deep red brown colour. By the 

 action of potassium also, phosphuretted hydrogen was obtained, and 

 by the action of acids on the residuum, it appeared that the potas- 

 sium had gained oxygen from the phosphorus; and the same inference 

 is drawn from the action of potassium on phosphuretted hydrogen, 

 which appears to contain oxygen in a state of combination, similar to 

 that which obtains in sulphuretted hydrogen. 



The same new modes of research are next employed to discover 

 what differences subsist in the states of carbonaceous matter, in 

 plumbago, charcoal, and diamond ; for though late and very accurate 

 experiments have proved that they yield very nearly the same quan- 

 tities of carbonic acid, it was nevertheless not improbable that new 

 means of analysis might detect chemical differences, correspondent to 

 the extreme difference of their physical properties. 



Plumbago, whether acted upon by the voltaic battery or by potas- 

 sium, yields no elastic product in either case ; but in the latter, 

 merely combines with the potassium unaltered. Charcoal, on the 

 contrary, by the voltaic apparatus, yielded a considerable quantity of 

 carburetted hydrogen, but did not contribute to the oxidation of the 

 potassium, any more than plumbago had done. 



The unconducting nature of the diamond rendered it impossible 

 to apply the voltaic battery with any effect, but it was by no means 

 insensible to the action of potassium. When these substances were 

 heated together, there was no intensity of action, and no production 

 of elastic fluid. But the diamond soon blackened at its surface, and 

 was ultimately reduced to a state perfectly resembling plumbago ; 

 part of it at the same time uniting to the potassium. The addition 

 of carbonaceous matter was not, however, the sole change that had 

 happened to the potassium, as it now extricated a smaller quantity 

 of hydrogen from water than an equal quantity of pure potassium, 

 and had evidently acquired a portion of oxygen from the diamond. 

 This quantity of oxygen (though certainly very small) is thought to 

 be the cause of its non-conducting quality. 



Mr. Davy next resumes the analysis of boracic acid, which he had 

 begun in his last Bakerian Lecture. By means of voltaic electricity, 

 a black matter could be obtained from it that was unaltered by water, 

 but soluble in nitric acid, and when heated to redness, burned slowly, 

 giving off white fumes. But the quantity of the base that could be 

 thus obtained was too minute for determining distinctly its relation 

 to the acid from which it was produced. However, by heating to- 

 gether boracic acid with potassium, a large quantity of a similar 

 matter (as has also been observed by M. Thenard) was obtained. In 



