WEiTE V. vsia. 223 �"Upon a faîlure by the licensee to mate retums, or to make paymeut of royalties, as berein provided, or to comply with any of his covenanta or agreements herein, the licensors may terminate this license by serving a written notice upon the licensee, or by learing Buch notice at the usual place of business of the licensee. But the licensee shall not thereby be discharged from any liabUity to the licensors, then accrued, whether due or not due." �The bill does not rely upon a written notice to terminate the license, and it is admitted that none bas been given; it merely avers that the defendant bas refused to pay for the invention, and has,"in ail other respects," failed and refused to perform his part of the agreement. This allegation is of too vague and general a nature to have much legal signifi- cance. �The defendant demurs to the relief, and I find his demurrer well taken. �The theory of the bill is that any f ailure by the licensee to pay the royalties, or to render an account, avoids the license immediately at the election of the licensor. A license is cften oompared to a lease of land, and many decisions foUow this analogy. Now, so far is equity from decreeing the for- feiture of a lease for a breach of covenant, it often interferes to crevent a forfeiture which would exist at law. I know of no case in which a mere failure to pay money, or keep some engagement of that nature, bas been held a good cause ^or asking a court of equity either to declare a forfeiture, or to proceed as if one had been incurred. �In some f ew patent cases, beginning with Brooks v. Stolley, 8 McLean, 623, it bas been held that a patentee enjoyed the unusual privilege of treating a breach of covenant as if it, of itself, worked a forfeiture^ No doubt the parties may agree that such an effect shall f oUow ; and this will account for some of the decisions. The others of this sort are overruled by Eartell v. Tïlghman, 99 U. S. 547. �The hardship of the doctrine contended for is manifest. The controversy in many of these cases, — and I understand this to be one of them, — is, whether a certain machine oz ����