why did emperor suggest to gulliver to send acouple of strulbrugs

From the text:

The king heard of all that had passed between me and my friends upon this occasion, and rallied me very pleasantly; wishing I could send a couple of struldbrugs to my own country, to arm our people against the fear of death; but this, it seems, is forbidden by the fundamental laws of the kingdom, or else I should have been well content with the trouble and expense of transporting them.