If any such persons are desirous of purchasing such lands, then within six weeks after such offer of sale, they shall signify their desire to purchase the lands, to the corporation; or if they decline such offer, or if for six weeks they neglect to signify their desire to purchase such lands, the right of preemption of every such person so declining or neglecting in respect of the lands included in the offer shall cease; and a declaration in writing made before a justice by some person not interested in the matter in question, stating that the offer was made and was refused or not accepted within six weeks from the time of making the same, or that the person or all the persons entitled to the right of preemption were out of the country, or could not, after diligent inquiry, be found, or were not capable of entering into a contract for the purchase of the lands, shall, in all courts, be sufficient evidence of the facts therein stated.