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.

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.

The distinction between the old and the new formulations consisting in the incorporation of the concept of the rate of chemical reactions is so great that it immediately asserted itself in the objective development of catalysis.

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.

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.

In the first quarter of the nineteenth century the experimental proof for the interdependence of the composition and properties of chemical compounds resulted in the theory that they are mutually related, so that like composition governs like properties, and conversely.