Bohr built on Nicholson's idea by adopting the requirement that the angular momentum can have only certain discrete values related to Planck's constant. However Bohr's atom has many orbits for the electrons.
The water in the hydrate (referred to as "water of hydration") can be removed by heating the hydrate. When all hydrating water is removed, the material is said to be anhydrous and is referred to as an anhydrate.