Occultists, from Paracelsus to Elephas Levi, divide the nature spirits into gnomes, sylphs, salamanders, undines; or earth, air, fire, and water spirits. Their emperors, according to Elephas, are named Cob, Paralda, Djin, Hicks respectively. The gnomes are covetous, and of the melancholic temperament. Their usual height is but two spans, though they can elongate themselves into giants. The sylphs are capricious, and of the bilious temperament. They are in size and strength much greater than men, as becomes the people of the winds. The salamanders are wrathful, and in temperament sanguine. In appearance they are long, lean, and dry. The undines are soft, cold, fickle, and phlegmatic. In appearance they are like man. The salamanders and sylphs have no fixed dwellings. It has been held by many that somewhere out of the void there is a perpetual dribble of souls; that these souls pass through many shapes before they incarnate as men--hence the nature spirits. They are invisible--except at rare moments and times; they inhabit the interior elements, while we live upon the outer and the gross. Some float perpetually through space, and the motion of the planets drives them. hither and thither in currents. Hence some Rosicrucians have thought astrology may foretell many things; for a tide of them flowing around the earth arouses there, emotions and changes, according to its nature. Besides those of human appearance are many animal and birdlike shapes. It has been noticed that from these latter entirely come the familiars seen by Indian braves when they go fasting in the forest, seeking the instruction of the spirits. Though all at times are friendly to men--to some men--"They have," says Paracelsus, "an aversion to self-conceited and opinionated persons, such as dogmatists, scientists, drunkards, and gluttons, and against vulgar and quarrelsome people of all kinds; but they love natural men, who are simple-minded and childlike, innocent and sincere, and the less there is of vanity and hypocrisy in a man, the easier will it be to approach them; but otherwise they are as shy as wild animals."