USE OF LOGIC IN SCIENTIFIC RESEARCH. 357 



when thus secured from atmospheric influence, it no longer 

 evolved the acid and alkali. 



' A formal analysis of these beautiful experiments will 

 illustrate the method of applying the rules of pure logic 

 in other cases. 



4 1. Statement of the case, the residual cause being 

 still undiscovered. 



' The decomposition of water by electricity produce& 

 oxygen and hydrogen, with an acid and an alkali. 



' II. Separation of the residual from the principal 

 cause. 



' a. The decomposition of water produces oxygen and 



hydrogen. 

 '6. The production of an acid and an alkali in the 



decomposition of water may be caused by action 011 



the glass vessel containing the water (Problematical 



Judgment). 



'III. The latter judgment, 6, disproved by a syllogism 

 with a conclusion that contradicts it. 



' A case in which I employ a vessel of gold cannot 

 evolve any decomposing action on a glass vessel. 



6 A case in which I employ a gold vessel still gives the 

 acid and alkali. 



6 Therefore cases of the production of the acid and alkali 

 are not always cases in which glass is decomposed. 



' IV. Another attempt to suggest the residual cause. 



' The acid and alkali are produced by the decomposition 



of impurities in the water employed. 

 4 Syllogism tending to prove this. 



4 An experiment with distilled water must admit less 



impurity. 



