How is putting salt on a slug chemical energy?

[1] Water always moves from areas of lower salt concentration to areas of higher salt concentration. [2] In a way, it's like the chemical process of transpiration in a plant. Water's pulled up from the roots, in liquid form. It passes out, in vaporized form, through openings ka stomata in leaves. [3] It's the same with slugs. The liquid in their bodies crosses out into the higher salt concentrations in the air and on the dehydrating slug's body, as water vapor.