At the same time, our memory will be enriched by a number of new subjects. The soul, beholding and understanding the worlds which surround it, will be able to fix the geography of all those different places in its memory. It will know the physical revolutions, the populations, and the legislation of these thousand countries. The superhuman being will know what exists in such planets and their satellites as come within his reach, or as he shall visit. Just as, in order to gain information, we visit America or Australia, so the superhuman being visits Mars or Venus, and furnishes his memory with millions of facts, which it retains and reproduces at will. What immense power must memory, always supplied and always ready at call, bestow on the mind and reason! Languages are only the expression and the assembling of ideas. Condorcet has said that a science always reduces itself to a well-constructed language. The mathematical sciences employ a language which is perfect, because the science of mathematics is perfect. The language spoken in the planetary spaces must be perfect, because it expresses all the knowledge of superhuman beings, and this knowledge is immense. The more the mind knows, the better it expresses:--the superhuman being, who is highly informed, will have a very expressive language, which will also be universal. The language of mathematics is understood by the peoples of both hemispheres. Algebra can be read by a Frenchman or a German, as well as by an Australian or a Chinese, on account of the simplicity and perfection of the conventional signs which it uses. The language of mathematics, which is truly universal, makes us infer that the language spoken in the planetary space must be also universal, and common, without distinction, to all the inhabitants of the ethereal worlds.