Cosmos, Vol. 5

according to which weighable substances combine according to specific proportional numbers This refers to the Law of Definite Proportions, a cornerstone of modern chemistry. The question raised by Prout William Prout (1785–1850), an English chemist, whether the atomic weights of all elementary substances (with the exception of chlorine and perhaps copper) are divisible by the atomic weight of a single one (hydrogen?), has been renewed with great ingenuity. The catalytic force, by which certain bodies exert a mysterious chemical activity in contact with others without the inducing bodies undergoing any change themselves, is a recognized but obscure, still unexplained force; according to Berzelius Jöns Jacob Berzelius (1779–1848), who coined the term 'catalysis', this force also manifests itself in many ways in the complex processes of organic life.

In the newly conquered field of electromagnetism, the following should be mentioned above all as broadening the horizon and promising even more important things than what has already been achieved: the true insight into the processes of induction; the specifically different influence of heterogeneous substances on the direction of the magnetic needle to which they are brought near: acting paramagnetically attracted to magnetic poles, like iron, cobalt, nickel, and oxygen—the latter in gaseous form and even in a very diluted state—while nitrogen gas itself, according to Plücker Julius Plücker (1801–1868), a German physicist and mathematician, is neither paramagnetic nor diamagnetic repelled by magnetic poles, but indifferent; the beautiful discovery according to which crystals are repelled or attracted in certain directions by the poles of a magnet; and finally the certainty attained that not only the periodicity of sunspots (the size and frequency of the funnel-shaped openings in the photosphere, which are absent from the equatorial and polar regions), but also the proximity of the sun acts upon terrestrial magnetism through the magnetic force inherent in its mass (Cosmos Vol. IV. p. 648). The intensity is greater