This case was originally heard as upon bill for injunction to restrain infringement of a patent, and was so reviewed by this court in 253 Mich. 324, and remanded for more testimony. Further hearing appears to have been upon the same issue, as no other contention was mentioned in the well-considered opinion of the circuit court holding that jurisdiction is in the Federal court.

Counsel for plaintiff concede that the State court has no jurisdiction in an action for infringement of a patent, but now claim that the suit is to enjoin violation and to enforce specific performance of an agreement, in the assignment of patent, to transfer improvements to plaintiff. The bill contained such a prayer.

In the former opinion this court said:

‘ ‘ The record is that defendants have no improvement. ’ ’

The preponderance of the testimony taken on remand was that the device complained of is not an improvement on the patent and was not an invention by any defendant but was prior art.

The decree dismissing. the bill for want of jurisdiction, but without prejudice to right of plaintiff to bring suit in Federal court, is affirmed, with costs.