Her work entitled _La Restitution de Pluton_ is a report on the mines and ore deposits of France, and is a document as precious as it is curious. It was addressed to Cardinal Richelieu, and shows how the French monarch could, if the subterranean treasures of the country were properly developed, become the greatest ruler in Christendom and his subjects the happiest of all peoples. Another report by this energetic and enthusiastic woman is in the same strain. In it she proves how the King of France, by utilizing the underground riches of his country, could make himself and his people independent of all other nations.[168] In these two productions Mme. de Beausoleil treats of the science of mining, the different kinds of mines, the assaying of ores and the divers methods of smelting them, as well as of the general principles of metallurgy, as then understood. But, unlike the majority of her contemporaries, this enlightened woman had no patience with those who believed that the earth's hidden treasures could not be discovered without recourse to magic or to the aid of demons. She was unsparing in her ridicule of those who had faith in the existence of gnomes and kobolds, or thought that ore deposits could be located only by divining-rods or similar foolish contrivances which were relics of an ignorant and superstitious age. The same century that witnessed the exploring activity of the Baroness de Beausoleil saw the beginnings of the notable achievements of a daughter of Germany, well known in the annals of science as Maria Sibylla Merian. Born in Frankfort in 1647, she died in Amsterdam in 1717, after a somewhat checkered career, most of which was devoted to the pursuit of natural history. So fond was she of flowers and insects that it is said they told her all their secrets. After having familiarized herself with the fauna and flora of her native land, she proceeded to investigate the collections of the principal European cabinets of natural history. This only fired her ambition to see more of the world and study Nature where she is seen in her greatest splendor and luxuriance. She accordingly resolved to undertake a journey to the equatorial regions of South America. Such a voyage can now be made with comparative ease, but in her days it was fraught with discomforts and dangers of all kinds, and one that no woman thought to venture on unless obliged to do so by stern necessity.