Commercial sodium dichromate is Hygroscopic and contains varying amounts of water.
"Organic-Syntheses"
Conant, James Bryant
This substance exists in the form of a gelatinous mass, cream-colored, very Hygroscopic.
"The Medicinal Plants of the Philippines"
T. H. Pardo de Tavera
There are some rocks, such as limestones, that are Hygroscopic, or possess the power of absorbing moisture from the air, and in dry climates such rocks are distinctly valuable, as the cementation of rock dust is in a large measure dependent for its full development on the presence of water.
"The Future of Road-making in America"
Archer Butler Hulbert