John Dalton

I have lately been prosecuting this inquiry with remarkable success. The principle cannot be entered upon in this paper; but I shall just subjoin the results, as far as they appear to be ascertained by my experiments.

Why does not water admit its bulk of every kind of gas alike? This question I have duly considered, and though I am not yet able to satisfy myself completely, I am nearly persuaded that the circumstance depends on the weight and number of the ultimate particles of the several gases.

The observation of the aurora borealis led me to suspect that the rays of light might be magnetically deflected.

My theory of mixed gases is founded on the principle that each gas is a vacuum to every other gas.

No new creation or destruction of matter is within the reach of chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen.

The elements of bodies are certain simple, or rather indivisible, particles of matter, which by combining together in various proportions, constitute the compound bodies.

When two elements combine to form more than one compound, the different masses of one element that combine with a fixed mass of the other are in a simple ratio of whole numbers.

I had a great desire to understand the nature of colour, and the cause of its variety in the different bodies.

It is one great object of this work, to show the importance and advantage of ascertaining the relative weights of the ultimate particles, both of simple and compound bodies, the number of simple elementary particles which constitute one compound particle, and the number of less compound particles which enter into the formation of one more compound particle.

The doctrine of definite proportions appears to me mysterious unless we adopt the atomic hypothesis.

I am of opinion that the particles of gases are not in contact with each other, but are acted upon by repulsive forces which keep them asunder.

On considering the foregoing facts, I am nearly persuaded that the circumstance depends on the weight and number of the ultimate particles of the several gases.

The most important investigations in physical science are those which relate to the ultimate particles of matter.

A mind which has once imbibed a taste for scientific inquiry, and has learnt the habit of applying its principles readily to the cases which occur, has within itself an inexhaustible source of pure and exciting contemplations.

I have chosen a path in life which offers few rewards, but I have pursued it with constancy, and have found in the pursuit itself my chief happiness.

If I have succeeded better than many who surround me, it has been chiefly, nay, I may say almost solely, from unwearied assiduity.

It is not so much from the number of facts, as from their connection and arrangement, that we are to look for the advancement of science.

The study of chemistry is the study of the laws which govern the combination of the elements.

The different sizes of the particles of elastic fluids under like circumstances of temperature and pressure being once established, it became an object to determine the relative sizes and weights, together with the relative numbers, of atoms in a given volume.

I ventured to predict that all the facts of chemistry would be explained on the principle of the atomic theory.