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A term used in the civil law, to signify that a contract is joint.

Obligations are in solido, first, between several creditors; secondly, between several debters. 1. When a person contracts the obligation of one and the same thing, in favor of several others, each of these is only creditor for his own share, but he may contract with each of them for the whole when such is the intention of the parties, so that each of the persons in whose favor the obligation is contracted, is creditor for the whole, but that a payment made to any one liberates the debtor against them all. This is called solidity of obligation. Poth. Obl. pt. 2, c. 3, art. 7. The common law is exactly the reverse of this, for a general obligation in favor of several persons, is a joint obligation to them all, unless the nature of the subject, or the particularity of the expression lead to a different conclusion. Evans' Poth. vol. 2, p. 56. See tit. Joint and Several; Parties to action.

An obligation is contracted in solido on the part of the debtors, when each of them is obliged for the whole, but so that a payment made by one liberates them all. Poth. Obli. pt. 2, c. 3, art. 7, s 1. See 9 M. R. 322; 5 L. R. 287; 2 N. S. 140; 3 L. R. 352; 4 N. S. 317; 5 L. R. 122; 12 M. R. 216; Burge on Sur. 398-420.