Definition of blue vitriol in English:

blue vitriol

noun

mass nounarchaic
  • Crystalline copper sulphate.

    • ‘For long, green vitriol was confused with blue vitriol, which generally occurs as an impurity in crude green vitriol.’
    • ‘The cost price of the product will be half the present price of blue vitriol at the world markets.’
    • ‘It is also possible to use blue vitriol while processing grain crops in storage and pickling seeds before sowing in order to eliminate fungi spores.’
    • ‘The member of doubles on the blue vitriol and nickel vitriol crystals is becoming more with increase in mass.’
    • ‘Any movement disturbs the delicate layers, ruining the battery, but if you're careful, you can drop in new crystals of blue vitriol as needed, and the battery will run for years.’