The doctrine of contribution is thus stated by Mr. Pomeroy in his work on Equity Jurisprudence:1

"Where there are two or more sureties for the same principal debtor, and for the same debt or obligation, whether on the same or on different instruments, and one of them has actually paid or satisfied more than his proportionate share of the debt or obligation, he is entitled to a contribution from each and all of his co-sureties, in order to reimburse him for the excess paid over his share, and thus to equalize their common burdens. The same doctrine applies, and the same remedy is given, between all those who are jointly, or jointly and severally, liable on contract or obligation in the nature of contract. The right, however, may be controlled or modified by express agreement among the co-sureties or debtors."

This doctrine grows out of the equitable maxim that "Equality is Equity," of which it is the chief application.

The right of contribution is now recognized in the courts of law, but the equitable relief, in this country, is more complete. Thus if one of the cosureties is insolvent, the co-surety who has paid the debt can at law only recover from the other co-sureties their proportional share, reckoned on the basis of the whole number of co-sureties, while in equity he can recover an amount determined by the number of solvent co-sureties.

1 Section 1418.

The right of contribution does not exist between sureties who are bound by separate instruments,2 nor does it ordinarily exist between joint tort fessors,3 but it has been enforced in a few cases of this character where the act was done without wrongful intent.4