ral expressions used in authorizing an agent are limited in application to acts done in connection with the act or business to which the authority primarily relates.'  Applying this rule to the power of attorney here in question it must be concluded that it conferred power only to deal with the German authorities and individuals with relation to Mrs. Peiffer's affairs in Wiesbaden and that it did not confer authority to assign her life estate in the realty in the Virgin Islands.  Accordingly, since Iza Callwood did not have authority under the power of attorney, properly interpreted, to execute the assignment of January 31, 1947 to Callwood, that assignment was rightly held by the district court to be invalid insofar as it sought to transfer Mrs. Peiffer's rights as life tenant of the real estate in St. Thomas.  We conclude for the reasons stated that the district court was right in denying Callwood's claim in toto.  We, therefore, need not consider the other grounds advanced in support of its action.


19
We pass then to the consideration of Mrs. Callwood's claim to a portion of the fund in controversy as assignee of Mrs. Peiffer by virtue of a verbal assignment alleged to have been made in August 1939.  Mrs. Callwood testified that this was intended to be an assignment of that portion of the future rents of the St. Thomas properties which had originally been owned beneficially by her husband Richard E. C. Callwood.


20
As we have already pointed out in connection with the assignment of January 31, 1947 to Callwood the validity of an assignment of future rents, being an assignment of an interest in land, is to be determined by the law of the situs of the land, in this case the Virgin Islands.  The applicable law in this regard is the statute of frauds which is in force in the Virgin Islands.  That statute provides that no interest in land, other than a lease for a term not exceeding one year, may be assigned or transferred except by a deed of conveyance or other instrument in writing.13  It follows that the ver