Cosmos, Vol. 5

(excluding the orbiting meteor-asteroids Humboldt refers here to small celestial bodies like meteoroids or fragments of comets) we only have to describe the activity of uniform types of matter; by contrast, the terrestrial part of the Cosmos reveals, alongside the dynamic effects of moving forces, the powerful and wondrously complex influence of specific differences in substances (Cosmos Vol. III. pp. 4 and 594). In this mentioned distinction between the complexity and the relative abundance of the material to be treated lies, in part, the cause (I dare not say the justification) for the exceedingly large interval of time between the publication of the individual volumes. The primary reason for this increasing delay, however, lies in the decline of the vital forces of an almost ninety-year-old man, when, despite unchanging nightly industriousness, less can be accomplished and with less cheerful confidence. Thus, since the time which I called "the late evening of a much-agitated life" in the preface to the first volume of Cosmos, more than twelve years have already passed.

When Descartes was working on his Cosmos, the Treatise on the World original: "le Traité du Monde", which was intended to encompass the "entire world of phenomena (the celestial sphere, as well as everything he knew of animate and inanimate nature)," he frequently broke out into bitter complaints in letters to his friend, Father Mersenne (which Baillet made known in 1691), regarding the slow progress of his work and the great difficulty of arranging so many subjects together (Works of Descartes original: "Oeuvres de Descartes", published by Victor Cousin 1824, Vol. I. p. 101; Cosmos Vol. III. p. 20). How much more bitter would the complaints of that philosopher—so diversely educated, even in anatomy—have been, had he reached the middle of the 19th cent-