6 
ON CHEMISTRY. 
constituents; and the decomposition of water by voltaic or galvanic 
electricity forms one of the most beautiful and decisive proofs of its 
compound nature, and also of the general correctness of Lavoisier’s 
deductions. If any doubt could by possibility have remained, it was 
removed by the converse of these experiments; that is, by the re¬ 
combination of the constituents, and the reproduction of the fluid 
“element.” I shall quote the substance of one of the most simple, 
and yet striking operations, the accuracy of which I can vouch, by 
the result of mine own experience. 
Into a large crystal balloon, or globular glass, a certain given por¬ 
tion of carefully purified oxygen gas was admitted. A reservoir of 
the same purified gas was also at hand, from which the balloon might 
be re-supplied. This vessel was exhausted of its air, by an air pump, 
previously to the admission of the oxygen gas ; and finally, by means 
of pressure, a small stream of hydrogen gas was made to pass into the 
balloon, which gas was immediately ignited by an electric spark. As 
the combustion proceeded, globules of water were deposited upon the 
inner surface of the globe, and these, enlarging into drops, ran down 
to the bottom of the vessel. I refer the reader to vol. I., page 144 
of Lavoisier’s Elements, for the particulars; suffice it to say—that it 
required eighty-five parts by weight of oxygen, united to fifteen parts 
of hydrogen, to compose one hundred parts of water. “We exerted” 
says the philosopher—“on that occasion, the most scrupulous atten¬ 
tion to accuracy ; and have reason to believe that the above propor¬ 
tions cannot vary a two hundredth part from absolute truth.” 
The compound decomposable nature of water cannot be a question 
of doubt; the nature also, and proportion of its elements are under¬ 
stood, as far as our limited knowledge will authorise this assertion; 
but there are depths and mysteries in all these phenomena which 
are at present unfathomable and incomprehensible. How are the 
two gases held in union, and condensed into the form of liquid ? By 
the abstraction, say the chemists, of their gaseous caloric which had 
previously kept them in a state of minute division ! But can this be 
the fact P It is true that in the slow combustion of hydrogen, in an 
atmosphere of oxygen gas, a great volume of heat is developed ; and 
in the case of the rapid combustion of a certain volume of the two 
gases blended together, a most violent explosion takes place. But 
then, light, as well as heat, is manifested, and what is light ? How is 
that produced from two invisible, aeriform fluids, unless it previouslv 
exist therein. 
1 shall not here anticipate what I must refer to at large in a future 
paper. I shall only observe that, in order to produce light, heat, 
