permanent hardness
Britishnoun
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Indeed, in the phraseology of a water-analyst, I may say that the sap itself has 25 degrees of total, permanent hardness.
From Scientific American Supplement, No. 385, May 19, 1883 by Various
Boiling the water does not affect these salts; hence such waters are said to have permanent hardness.
From An Elementary Study of Chemistry by William McPherson
Calcium sulphate, or gypsum, on the other hand, imparts permanent hardness.
From Human Foods and Their Nutritive Value by Harry Snyder
There are water supplies whose hardness can be corrected and there are supplies of the type known as "permanent" hardness.
From The Consumer Viewpoint by Mildred Maddocks
What do the terms "temporary" and "permanent" hardness of water mean?
From Human Foods and Their Nutritive Value by Harry Snyder
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
