Is it farther or further?
1650s, from Latin permeatus, past participle of permeare "to pass through" (see permeable). Related: Permeated; permeating.
permeate per·me·ate (pûr'mē-āt')v. per·me·at·ed, per·me·at·ing, per·me·ates
To spread or flow throughout; pervade.
To pass through the openings or interstices of, as a liquid through a membrane.