Practical Observations concluding John Davies's Patent Cases (1816)
Installment 4 of 6: Voiding Patents by Writs of Scire Facias

Reproduced below is material from Practical Observations concluding John Davies, A Collection of the most Important Cases relating to Patents of Invention (1816). In view of its length and detail, this concluding section of the book is being posted on the blog in six installments.
This fourth installment concerns the procedure for voiding patents through writs of scire facias.

---

Having shortly stated what is the previous use of a thing which will vitiate a patent, it may be proper to shew for what other causes a patent may be set aside, and by what means.
A writ of scire facias to repeal letters patent lies in three cases: first, when the king doth grant by several letters patent one and the self same thing to several persons, the first patentee may have a scire facias to repeal the second, because it is granted to the prejudice of the first, and the king of right is to permit him, upon petition, to use his name for the repeal of it.
Secondly, when the king doth grant a thing upon a false suggestion, he, by his prerogative, may by scire facias repeal his own grant. A patent may be said to be obtained upon a false suggestion, if it is to the prejudice of the crown or the community, or hurtful to trade by raising the price of the commodity, or in any other way contrary to the terms of the statute of 21 Jac.
And thirdly, when the letters patent express a grant which, by the law of the land, the king cannot make. This may be either against the common law, the statute law, or both, by interfering with the industry of the people, or granting the sole use of any known trade or art, and various other ways which it is not necessary here to enumerate.
A scire facias should be founded upon some record, and therefore to repeal a patent it ought to be in Chancery, where the patent it ought to be in Chancery, where the patent is recorded. The record of the proceedings upon the writ is made up in that court and sent to a court of law to be tried.
But it should be observed that it is not every mistake in a grant which will vitiate a patent, as will be seen by the following general rules laid down by Chief Justice Lee. [NOTE: Buller's Nisi Prius, p. 75.]
1st. Every false recital in a thing not material will not vitiate the grant, if the king's intention is manifest and apparent.
2dly, If the king is not deceived in his grant by the false suggestion of the party, but from his own mistake, upon the surmise and information of the party, it shall not vitiate or avoid the grant.
3dly, Although the king is mistaken in point of law, or matter of fact, if that is not part of the consideration of the grant, it will not avoid it.
4thly, When the king grants ex certa scientia et mero motu, those words occasion the grant to be taken in the most liberal and beneficial sense according to the king's intent and meaning expressed in his grant.
5thly, Although in some cases the general words of a grant may be qualified by the recital, yet if the king's intent is plainly expressed in the body of the grant, the intent shall prevail and take place.