“One cannot help feeling that the barrier which exists between the organized and unorganized worlds is one which the chemist at present sees no chance of breaking down. It is true that there are those who profess to foresee that the day will arrive when the chemist, by a succession of constructive efforts, may pass beyond albumen, and gather the elements of lifeless matter into a living structure. Whatever may be said regarding this from other standpoints, the chemist can only say that at, present no such problem lies within his province. Protoplasm, with which the simplest manifestations of life are associated, is not a compound, but a structure built up of compounds. The chemist may successfully synthesize any of its component molecules, but he has no more reason to look forward to the synthetic production of the structure than to imagine that the synthesis of gallic acid leads to the artificial production of gall-nuts.”

A 2015 rendition of the Roscoe periodic table, conceived by Henry Roscoe (c.1900), based on the Henry Bray (1910) description.

“Let us in our minds write on our mental blackboard the names of the Englishman Newlands, the Frenchman Dumas, the German Meyer, and the Russian Mendeljeff, all written in a horizontal line; next let us write beneath the name of each of these men the name of his father, and beneath that the name of his grandfather, and beneath that the name of his great-grandfather, and so on. If you now write opposite the name of each of these individuals the number of years since his birth, you will find the numbers will increase by a definite increment, namely the age of a generation, which will be approximately the same in all the families. There will be certain differences in the ages of the chemists themselves, but such differences will be little when compared to the period that will be found has elapsed since the birth of any of their ancestors. In these family-trees, each individual takes the place, as it were, of a chemical element: as each family is marked by certain peculiarities, so each group of atoms thus arranged show marked and unmistakable signs of a common origin.”

“In such a family-tree as we have mentioned, it may frequently happen that the history of some member of the family has been entirely lost. When such is the case it is not impossible, especially for a man like Francis Galton, to judge from the known history of the other members what the characteristics of the missing member of the family must have been. It is thus as to atoms. It was not long ago when Mendeljeff said that if certain vacancies in his tables of atoms were ever filled, they would have to be filled by elements possessing certain chemical and physical properties which he accurately specified. Since that time these vacancies have been filled, and by atoms or elements possessing the very properties which Mendeljeff said they would possess.

Galium was discovered by Lecoq de Boisbaudron, scandium by Nilson, germanium by Winkler; and these discoverers agree that the atomic, chemical, and physical properties of these substances agree exactly with those predicted by Mendeljeff. It sometimes happens that the real parentage of an element has been lost altogether, but a careful examination frequently enables the chemist to restore it to the family to which it belongs.”