alkali vs saline

alkali

noun
  • Soluble mineral matter, other than common salt, contained in soils of natural waters. 

  • One of a class of caustic bases, such as soda, soda ash, caustic soda, potash, ammonia, and lithia, whose distinguishing characteristics are dissolving in alcohol and water, uniting with oils and fats to form soap, neutralizing and forming salts with acids, turning to brown several vegetable yellows, and changing reddened litmus to blue. 

saline

noun
  • Water containing dissolved salt. 

  • A salt spring; a place where salt water is collected in the earth. 

adj
  • Resembling salt. 

  • Containing salt; salty. 

How often have the words alkali and saline occurred in a corpus of books? (source: Google Ngram Viewer )