Both solea and solum are, of course, from the same root.
Suarez maintains that, though the humanity of Socrates does not differ from that of Plato, yet they do not constitute realiter one and the same humanity; there are as many "formal unities" (in this case, humanities) as there are individuals, and these individuals do not constitute a factual, but only an essential or ideal unity ("ita ut plura individua, quae dicuntur esse ejusdem naturae, non sint unum quid vera entitate quae sit in rebus, sed solum fundamentaliter vel per intellectum").
This was due to a confusion with solum, ground, whence Fr.
The station here has been demolished although the solum of the line remains intact.
It is from John Mair's Historia Majoris Britanniae tam Angliae quam Scotiae, which appeared in 1521 "Circa haec tempora [Ricardi Primi], ut auguror, Robertus Hudus Anglus et Parvus Joannes latrones famatissimi in nemoribus latuerunt, solum opulentorum virorum bona deripientes.