iodides

or sulphates) in appreciable amounts. soft w., one which contains a minimum amount of salts of calcium or magnesium, in which soap di olves without a sediment, sul'phate w., one holding in solution appreciable quantities of the sulphates of calcium, magnesium, or sodium. sul'phur w., one containing sulphureted hydrogen or the metallic sulphides, sur'face w., the w. of ponds, lakes, or streams, ther'mal w.,- a w. which is hot as it i ues from the spring. w. of adhe's ion, water held by molecular attraction in contact with units of structure, but not forming an e ential part of their constitution, w. of constitu'tion, water held by a unit of structure as an e ential part of its constitution, though not an ingredient of its molecules, w. of ciystalliza'tion, w. of constitution which imites with certain salts and is e ential to their arrangement in crystalline form.