2l5 O^ THE COMBINATIONS OF OXIQEN. 



Production of And here I cannot help observing, that a ver)'^ beautiful 

 heat atu. light appi-,(.atJoi^ ,n^y ^g made of this circumstance, to explain 

 tionofsulphu- the production of heat and light during the formation of 

 ■'"*• these sulphurets, a difficulty hitherto inexplicable. It is 



well known, that oxigen in some of its combinations retains 

 more of light and heat than in others, now here is the tran- 

 sition of oxigen, as contained in sulphur, to a metal; it is 

 by no means improbable, that in the latter compound it 

 may be disposed to retain less of the light and heat than in 

 the former; if this be the case, the appearances during the 

 operation no longer present any difficulty. 

 Cnioncfalka- The only other circumstance, which occurs in objection 

 4is with oil. jQ j.j^g above propositions, is the combination of alkali and 

 oil ; and this objection also is very readily satisfied. "When 

 *' the oil is separated by an acid from soap, it is affirmed, 

 *• that in several respects its properties are altered, and that 

 •• in particular it is soluble in alcohol. During its con- 

 '* version into soap, therefore, it must not merely have 

 '^* combined with the alkali, but have undergone some other 

 ♦' change*." But a short quotation from La Grange is still 

 more to the purpose. " There is," he says, " an absorp- 

 *' tion of oxigen during the process of saponification ; that 

 •' is to say, the oil becomes concrete by absorbing oxigen." 

 Solution of There is indeed still another compound, which may be 



'V.'^^^""" " urged as unfavourable to this doctrine, viz. the solution of 



phosphorus ° 



vtHh oil. sulphur and phosphorus in oil, but it is equally invalid with 



the former, and another quotation from Mr. Murray's ex- 

 cellent work will again calm the clamour of objection. It 

 has been remarked, that sulphur and phosphorus contain 

 oxigen ; now this is the composition of oil in the words of 

 Mr. Murray. Lavoisier hence inferred, " that oil contains 

 *' 79 parts of carbon united to 21 of hidrogen. These must 

 *' however be regarded as approximations only ; and oxigen 

 " is probably also a constituent part of oil. That it is so 

 *' appears to be established by the decomposition of oil in 

 ** close vessels ; wHen transmitted through an ignited tube, 

 ** carbonic acid and water are part of the products." 



It is however evident, that these observations are intended 

 to apply in cases more simple than to vegetable comppunds, 



f Murray. 



in 



