25. Agreements void if considerations and objects unlawful in part

If any part of a single consideration for one or more objects, or any one or any part of any one of several considerations for a single object, is unlawful, the agreement is void.

Illustration

A promises to superintend, on behalf of B, a legal manufacture of indigo and an illegal traffic in other articles. B promises to pay to A a salary of $10,000 a year. The agreement is void, the object of A’s promise and the consideration for B’s promise, being in part unlawful.