For the man sound of body and serene of mind, there is no such thing as bad weather, every day has its beauty. And storms which whip the blood, do but make it pulse more vigorously.——George Gissing
乔治•吉心（英国小说家，散文家，著有《四季随笔》）：对于身体健全，心境平静的人而言，根本没有坏天气，无论什么天气都有其美好的一面。激荡血液流淌的暴风雨，只会使脉搏跳动得更加有力。(Hotch)

do make为强调谓语的肯定性。but为副词，意为仅仅、只。

I do but love you. = I do only love you. = I only love you.