"He formulated, as the fundamental law of the physico-chemical sciences, the dictum that "all the properties of bodies are periodic functions of their atomic weights"... on reaching this point of its development, the conception of Prof. Mendeleev becomes essentially injurious. Under the pretext of a law which has still to be demonstrated, it forbids us to throw light upon pure matters of observation, and forces us to remain in a vicious circle from which there is no escape. I think that it is time to show clearly that there is nothing [here] which merits the name of law or system."