the best quarry for a friend hunter

. . . A heart formed for the gentler emotions of the soul often feels as strong an interest for what are called brutes, as most bipeds affect to feel for each other. Montaigne had his cat; I have read of a man whose only friend was a large spider; and Trenek, in his dungeon, would sooner have lost his right hand than the poor little mouse, which, grown confident with indulgence, used to beguile the tedious hours of imprisonment with its gambols. 

For my own part, 1 believe my dog, who, at this moment, seated on his under legs, is wistfully surveying me, as if he was conscious of all that is passing in my mind,—my dog, I say, is as sincere, and, whatever the world may say, nearly as dear a friend as any I possess; and, when I shall receive that summons which may not now be far distant, he will whine a funeral requiem over my grave more piteously than all the hired mourners in Christendom. Well, well, poor Bob has had a kind master of me, and, for my own part, I verily believe there are few things on this earth I shall leave with more regret than this faithful companion of the happy hours of my infancy.

-- Henry Kirke White, from an essay titled "The Friend Hunters,"in The Beauties of Henry Kirke White, consisting of selections from his poetry and prose (Boston: N. H. Whitaker, 1827) pp. 182-3

Trenek seems to have been a Prussian baron with a harrowing tale of years of capture, if I've found the right book.