Colloid

If a number of substances be arranged in a series according to their relative diffusibilities, we find at one end of the list a number of substances of slow diffusibility, such as starch and albumen, which have in general an amorphous, gluelike character; these are colloids. Substances at the other end of the list, of rapid diffusibility, such as urea and chloride of sodium, are called crystalloids. The former will not diffuse through vegetable or animal membranes. generation has taken place, there are numerous collections of glue-like material.