THE REVIVED THEORY OF PHLOGISTON. 565 



of decisive experiments ; I will select a few, which may at the same time con- 

 firm what has been advanced concerning the constituent parts of sulphur. 



" From the analysis or decomposition of sulphur effected by burning, we 

 have concluded that the constituent parts of sulphur are two an acid which 

 may be collected, and an inflammable principle which is dispersed. If the 

 reader has yet acquired any real taste for chemical truths, he will wish to see this 

 analysis confirmed by synthesis ; that is, in common language, he will wish to 

 see sulphur actually made by combining its acid with an inflammable principle. 

 It seldom happens that chemists can reproduce the original bodies, though 

 they combine together all the principles into which they have analyzed them ; 

 in the instance, however, before us, the reproduction of the original substance 

 will be found complete. 



" As the inflammable principle cannot be obtained in a palpable form sepa- 

 rate from all other bodies, the only method by which we can attempt to unite it 

 with the acid of sulphur must be by presenting to that acid some substance in 

 which it is contained. Charcoal is such a substance; and by distilling powdered 

 charcoal and the acid of sulphur together, we can procure a true yellow sul- 

 phur, in no wise to be distinguished from common sulphur. This sulphur is 

 formed from the union of the acid with the phlogiston of the charcoal ;' and 

 the charcoal may by this means be so entirely robbed of its phlogiston that it 

 will be reduced to ashes, as if it had been burned. . . . 



" I will in this place, by way of further illustration of the term phlogiston, 

 add a word or two concerning the necessity of its union with a metallic earth, 

 in order to constitute a metal. Lead, it has been observed, when melted in a 

 strong fire, burns away like rotten wood ; all its properties as a metal are de- 

 stroyed, and it is reduced to ashes. If you expose the ashes of lead to a strong 

 fire they will melt ; but the melted substance will not be a metal, it will be a 

 yellow or orange-colored glass. If you pound the glass, and mix it with char- 

 coal-dust, or if you mix the ashes of the lead with charcoal-dust, and expose 

 either mixture to a melting heat, you will obtain, not a glass, but a metal, in 

 weight, color, consistency, and every other property, the same as lead. The 

 ashes of lead melted without charcoal become glass ; the ashes of lead melted 

 with charcoal become a metal. The charcoal, then, must have communicated 

 something to the ashes of lead, by which they are changed from a glass to a 

 metal. Charcoal consists of but two things of ashes and of phlogiston ; the 

 ashes of charcoal, though united with the ashes of lead, would only produce 

 glass ; it must, therefore, be the other constituent part of charcoal or phlogis- 

 ton which is communicated to the ashes of lead, and by a union with which 

 the ashes are restored to their metallic form. The ashes of lead can never be 

 restored to their metallic form without their being united with some matter con- 

 taining phlogiston, and they may be reduced in their metallic form by being united 

 with any substance containing phlogiston in a proper state, whether that sub- 

 stance be derived from the animal, vegetable, or mineral kingdom ; and thence 

 we conclude, not only that phlogiston is a necessary part of a metal, but that 

 phlogiston has an identity belonging to it, from whatever substance in Xature 

 it be extracted. And this assertion still becomes more general, if we may be- 

 lieve that metallic ashes have been reduced to their metallic form, both by the 

 solar rays and the electrical fire." 



The foregoing account by Dr. Watson is almost a translation from 

 Stahl's " Zymotechnica Fundamentalis, simulque experimentum no- 



