Elementaries. Properly, the disembodied souls of the depraved; these souls having at some time prior to death separated from themselves their divine spirits, and so lost their chance for immortality; but at the present stage of learning it has been thought best to apply the term to the spooks or phantoms of disembodied persons, in general, to those whose temporary habitation is the Kâma Loka. Eliphas Lévi and some other Kabbalists make little distinction between elementary spirits who have been men, and those beings which people the elements, and are the blind forces of nature. Once divorced from their higher triads and their bodies, these souls remain in their Kâma-rupic envelopes, and are irresistibly drawn to the earth amid elements congenial to their gross natures. Their stay in the Kâma Loka varies as to its duration; but ends invariably in disintegration, dissolving like a column of mist, atom by atom, in the surrounding elements.
Source: H.P.Blavatsky - The Theosophical Glossary