water-glass

A student uses a water-glass to observe a submerged object in chemistry class.

Definition

1. Noun:
   • A tube for observing underwater objects: "water-glass" refers to a cylindrical tube or device with a glass bottom that allows a person to see beneath the surface of water, typically used for observing aquatic life or underwater objects.
   • A solution of sodium silicate: In chemistry, "water-glass" is a common name for a solution of sodium silicate (Na₂SiO₃), which is used as a preservative for eggs, a fireproofing agent, or an adhesive.

Usage Examples

• Noun (observation tube):

  • The marine biologist used a water-glass to study the coral reef without getting wet. (A tube with a glass bottom for underwater viewing.)
  • Children at the beach often use a water-glass to look at shells and fish below the surface. (A simple device for seeing underwater.)

• Noun (chemical solution):

  • Farmers used a water-glass coating to preserve fresh eggs for several months. (Sodium silicate solution applied to eggs to seal them.)
  • The fireproofing material was made from water-glass, which hardens when exposed to heat. (A solution of sodium silicate used as a fire retardant.)

Advanced Usage

• "to coat with water-glass": to apply a layer of sodium silicate solution to a surface for preservation or protection.

  • The museum coated the ancient pottery with water-glass to prevent further decay. (Applied a preservative layer of sodium silicate.)

• "water-glass technique": a method in microscopy or chemistry using sodium silicate as a mounting medium or binder.

  • The water-glass technique was used to fix the specimen on the slide. (A specific procedure involving sodium silicate.)

Variants and Related Words

• Water glass (n): the same as "water-glass," often written as two words, meaning either the observation tube or the chemical solution.

  • He peered through his water glass at the riverbed. (The observation device.)
  • Sodium silicate is commonly called water glass in industrial contexts. (The chemical solution.)

• Sodium silicate (n): the chemical compound that constitutes water-glass.

  • Sodium silicate is a key ingredient in many detergents and adhesives. (The formal name for water-glass.)

Synonyms

• Observation tube: a cylindrical device for viewing underwater (specific to the first meaning).
• Sodium silicate solution: the chemical compound (specific to the second meaning).
• Liquid glass: another common name for sodium silicate solution.

Phrasal Verbs (None directly related)

• None: "water-glass" is a noun and does not form phrasal verbs.

Related Idioms (None)

• None: "water-glass" is not used in common idiomatic expressions.