My only supporter and comrade-in-arms was Georg Helm, who had endeavored to formulate an energetic conception of science before me and had presented his results in a treatise [Die Lehre von der Energie] exhibiting great independence of thought. But we were separated by his aversion to a realistic conception of energy. Consequently, each of us considered the other only a half ally, toward whom an attitude of caution was necessary.

We know from biology that new forms of organisms simulate their primitive form as closely as possible at first, even though obliged to exist under changed internal and external conditions.

Science is one land, having the ability to accommodate even more people, as more residents gather in it; it is a treasure that is the greater the more it is shared. Because of that, each of us can do his work in his own way, and the common ground does not mean conformity.

The individual organs follow the same pattern as the whole organism, i.e. they have their period of growth, of stationary, maximum activity and then of aging decline.

It has pleased no less than surprised me that of the many studies whereby I have sought to extend the field of general chemistry, the highest scientific distinction that there is today has been awarded for those on catalysis.

Nowadays, however, we recognize that simultaneously with the typical case of a chemical reaction a typical case of catalytic effect had been studied which constitutes a limiting case.

For, with pure water the inversion of cane sugar scarcely proceeds and subsequently it required very thorough, difficult studies before this effect and its order of magnitude were established.