Similarly, volume does not make a difference, per say. What matters is the gradients between the internal system (body) and the external environment, across the skin. Thus it is not volume that matters, but the concentration of solutes in the body and external liquid. Diffusion is governed by the same laws in both cases, save for things like active transport etc. inside the body. But in both cases the 'scale' is at the molecular level, i.e. the movement of water molecules and ions from one area to another....
