On definite Proportions. 371 
The only point to be discussed is, What are those two ele- 
ments? There are a thotsand questions of the like nature, 
that cannot be answered. What is gravity, or magnetism ? 
All we know of them is derived from the effects which they 
produce. 
The astronomer knows how to calculate the revolutions 
of the celestial bodies to a mathematical exactness, upon 
the unknown element of gravitation ; and the mariner can 
navigate unknown seas by his compass, without knowing 
the cause that turns the needle to the pole. And men pre- 
dict a thousand effects from causes equally unknown. 
Of the animal and vegetable kingdoms we know nothing 
but what we see. An egg becomes a bird, and flies away ; 
and a bulbous root, planted in the earth, produces a flower 
which displays more beautiful tints than those of the rain- 
bow. These phenomena are known to every child; but 
the causes of those wonderful effects ‘are hidden from every 
human eye. In short, men reason from the effects of 
unknown causes, and act accordingly with the same con- 
fidence as if those causes were perfectly understood. 
Hence, if we adopt the two invisible imponderable active 
powers, collected by the electric machine, as the elements 
of combustion, we do not deviate from the best modes of 
investigating truth. ; 
Lynn, Nov, 15, 18i3. Ez. WALKER. 
[To be continued.]} : 
LXI. An Attempt to determine the definite and simple Pro- 
portions, in which the constituent Parts of unorganic Sub- 
stances are united with each other. By JacoB BerzE- 
ius, Professor of Medicine and Pharmacy; and M.R.A. 
Stockholm. 
lV. THe Carponic ACID. 
The carbonic acid in combination contains either twice or 
four times as much oxygen as the base. 
Arthe time of my first investigations relating to carbonates, 
I was unacquainted with M. Gay-Lussac’s determination 
of the component parts of the carbonic acid. I had taken 
for their proportion 71;56 of oxygen, and 28°43 of carbon, 
according to the experiments of MM. Alien and Pepys, 
My analyses did not perfectly agree with this proportion ; 
but I supposed the cause of the disagreement to depend 
rather on my experiments than on those of the English 
Aag2 chemists. 
