The proper law of a trust deed is determined by the same tests as are applicable in determining the proper law of a contract. Where no actual intention appears either by implication or necessary intendment, the presumed or constructive intention of the parties is to be sought in the nature and the subject matter of the deed, its incidents, the situation of the parties, such other matters as must have been within their contemplation, the circumstances of the transaction, the place where its terms are to be carried out, and the place with which the transaction has the most real and substantial connection. The place where the deed is executed may be a mere matter of convenience.