John Dalton

The atomic theory is not a recent invention; it is an ancient doctrine revived and established upon experimental evidence.

My work has been that of a pioneer, and as such it must be judged.

The laws of chemical combination are the foundation upon which the whole science of chemistry is built.

In all chemical investigations, it has justly been considered an important object to ascertain the relative weights of the atoms which constitute a compound body.

The atmosphere is not a vast chemical solvent, nor is it a mere mechanical mixture; it is a dynamic equilibrium of elastic fluids.

I was first led to the subject by observing the variegated colour of the sky.

I am aware that the atomic theory is still viewed with suspicion by many, but I am confident that time will confirm its truth.

The particles of one gas are not attracted by those of another gas, but each gas diffuses itself independently through the other.

To comprehend the laws which regulate the combination of bodies, we must know the weights of their ultimate particles.

The force of steam from all liquids is the same at equal distances above or below the several temperatures at which they boil in the open air.

I have been accused of being a theorist, but my theories are the result of long and patient experiment.

The science of chemistry is yet in its infancy, but its progress will be rapid now that a true foundation has been laid.

Colour-blindness is not a disease, but a peculiarity of vision.

My brother and I both saw colours differently from other people.

The particles of a gas are in a state of constant and rapid motion.

The pressure of a mixture of gases is equal to the sum of the pressures each would exert if it alone occupied the container.

Water is a binary compound of hydrogen and oxygen, and the relative weights of the two elementary atoms are as 1:7, nearly.

Nitrous gas is a compound of one atom of nitrogen and one atom of oxygen; nitric acid is a compound of one atom of nitrogen and two atoms of oxygen.

The atomic theory affords a simple explanation of the law of definite proportions.

All the changes that take place in the material world are the result of combinations or separations of atoms.