“The discovery of the agencies of the gases destroyed the hypothesis of Stahl. The knowledge of the powers and effects of the etherial substances may at a future time possibly act a similar part with regard to the more refined and ingenious hypothesis of Lavoisier; but in the present state of our knowledge, it appears the best approximation that has been made to a perfect logic of chemistry.”
Led by analogy, Davy soon convinced himself that the volatile alkali--ammonia--also contained oxygen, and in amount not less than 7 or 8 per cent. It is not necessary to go into detail concerning the experiments on which this erroneous conclusion was founded. Davy was subsequently made aware of his error; but at the time he seemed anxious to overturn--as, indeed, he did in the end, but on other grounds--the Lavoisierian doctrine that oxygen was the principle of acidity, by showing that it was equally the principle of alkalescence.
In concluding his paper, he mentions that he has begun experiments on the alkaline earths.
“From analogy alone it is reasonable to expect that the alkaline earths are compounds of a similar nature to the fixed alkalies, peculiar highly combustible metallic bases united to oxygen. I have tried some experiments upon barytes and strontites, and they go far towards proving that this must be the case.”
“Barytes and strontites have the strongest relations to the fixed alkalies of any of the earthy bodies; but there is a chain of resemblances through lime, magnesia, glucina, alumina, and silex. And by the agencies of batteries sufficiently strong, and by the application of proper circumstances, there is no small reason to hope that even these refractory bodies will yield their elements to the methods of analysis by electrical attraction and repulsion.”
Although certain of the conjectures with which the paper terminates have been proved to be erroneous, others have been shown to be sound. Thus he points out that the metals of the alkalis will undoubtedly prove powerful agents for analysis:
“Having an affinity for oxygen stronger than any other known substances they may possibly supersede the application of electricity to some of the undecompounded bodies.”
Such is a brief summary of the contents of one of the most classical papers in the _Philosophical Transactions_. Its publication created an extraordinary sensation, not less profound, and certainly more general from the very nature of the subject, than that which followed his first Bakerian lecture. That potash and soda should contain metals--and such metals!--was undreamt of, and was a shock to the settled convictions of persons who, like the Aberdonian professor, declared that this “ane Davy was a vera troublesome person in chemistry.”