390 Sir Humphry Davy on the relations of 
different modifications , was the cause of all the phenomena exhi- 
bited by different Voltaic combinations. 
Believing that our philosophical systems are exceedingly 
imperfect, I never attached much importance to this hypo- 
thesis ; but having formed it after a copious induction of 
facts, and having gained immediately by the application of it 
a number of practical results, and considering myself as 
much the author of it as I was of the decomposition of the 
alkalies, and having developed it in an elementary work, as 
far as the present state of chemistry seemed to allow, I have 
never criticised or examined the manner in which different 
authors have adopted or explained it, — contented, if in the 
hands of others it assisted the arrangements of chemistry or 
mineralogy, or became an instrument of discovery. And 
having now given what I believe to be a faithful sketch of its 
origin, I shall not enter into an examination of those works 
which have induced me to make this sketch, and which con- 
tain partial or loose statements on the subject, and which 
refer the origin of electro-chemistry to Germany, Sweden 
and France, rather than to Italy and England and which 
attribute some of the views of the science, which I first deve- 
loped, to philosophers who have never made any claim of the 
kind, and who never could have made any, as their works 
on the subject were published many years after 1806. 
III. On the modes adopted for detecting the electrical states of 
bodies , and definitions of terms. 
That the statements made in the following sections may 
be more distinct, I shall say a few words of the mode in 
which the different conditions of electrical action were ascer- 
