The microscopic source of all motion

I am presence, a portion of the great unseen multitude of beings, who are continually passing presence, like a shadow, over the face of the earth. My amount of weight is inconsiderable, my presence is only to be detected by the help of the microscope, and my course can be easily traced by the help of the telescope. I am perpetually shifting, but my presence is constantly maintained, for I am never totally absent from any place, my amount being reckoned by millions of individuals. I am a part of the life of all animated beings, and my existence contributes to the support of their presence. I am the unseen source of all motion, and the unseen presence of all that is visible. I am the spirit of the presence of your servants, and your own presence is dependent upon me. I