There are other cases which somewhat resemble this of accession, but which, at the bottom, are considerably different, and merit our attention. Of this kind is the conjunction of the properties of different persons, after such a manner as not to admit of _separation_. The question is, to whom the united mass must belong. Where this conjunction is of such a nature as to admit of _division_, but not of _separation_, the decision is natural and easy. The whole mass must be supposed to be common betwixt the proprietors of the several parts, and afterwards must be divided according to the proportions of these parts. But here I cannot forbear taking notice of a remarkable subtilty of the Roman law, in distinguishing betwixt _confusion_ and _commixtion_. Confusion is an union of two bodies, such as different liquors, where the parts become entirely undistinguishable. Commixtion is the blending of two bodies, such as two bushels of corn, where the parts remain separate in an obvious and visible manner. As in the latter case the imagination discovers not so entire an union as in the former, but is able to trace and preserve a distinct idea of the property of each; this is the reason why the _civil_ law, though it established an entire community in the case of _confusion_, and after that a proportional division, yet in the case of _commixtion_, supposes each of the proprietors to maintain a distinct right; however, necessity may at last force them to submit to the same division. _Quod si frumentum Titii frumento tuo mistum fuerit: siquidem ex voluntate vestra, communc est: quia singula corpora, id est, singula grana, quæ a cujusque propria fuerunt, ex consensu vestro communicata sunt. Quod si casu id mistum fuerit, vel Titius id miscuerit sine tua voluntate, non videtur id communc esse; quia singula corpora in sua substantia durant. Sed nec magis istis casibus commune sit frumentum quam grex intelligitur esse communis, si pecora Titii tuis pecoribus mista fuerint. Sed si ab alterutro vestrum totum id frumentum retineatur, in rem quidem actio pro modo frumenti cujusque competit. Arbitrio autem judicis, ut ipse æstimet quale cujusque frumentum fuerit_. Inst. Lib. II. Tit I. § 28.