destructively

— In one locality, on our journey, we saw some horses that had been born and reared on top of the mountains, above the range of running water, and consequently they had never drank that fluid in their lives, but had been always accustomed to quenching their thirst by eating dew-laden or shower-wetted leaves. And now it was destructively funny to see them sniff suspiciously at a pail of water, and then put in their noses and try to take a bite out of the fluid, as if it were a solid. Finding it liquid, they would snatch away their heads and fall to trembling, snorting and showing other evidences of fright. When they became convinced at last that the water was friendly and harmless, they thrust in their noses up to their eyes, brought out a mouthful of water, and proceeded to chew it complacently.https://en.wikisource.org/wiki/Roughing_It/Chapter_LXXVI