"Rochelle salt" meaning in English

{
  "etymology_text": "From La Rochelle in France.",
  "forms": [
    {
      "form": "Rochelle salts",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Rochelle salt (plural Rochelle salts)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Inorganic compounds",
          "orig": "en:Inorganic compounds",
          "parents": [
            "Matter",
            "Chemistry",
            "Nature",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1998, Georgina Ferry, Dorothy Hodgkin: A Life:",
          "text": "In fact, at the current state of knowledge and technology, probably only the simplest of the structures she worked on in Cambridge, Rochelle salt, could have been fully solved at the time.",
          "type": "quote"
        }
      ],
      "glosses": [
        "The double salt potassium sodium tartrate tetrahydrate (KNaC₄H₄O₆·4H₂O), used for various scientific and medical purposes."
      ],
      "id": "en-Rochelle_salt-en-noun-HzNBWUq6",
      "links": [
        [
          "inorganic chemistry",
          "inorganic chemistry"
        ],
        [
          "double salt",
          "double salt"
        ],
        [
          "potassium sodium tartrate tetrahydrate",
          "potassium sodium tartrate tetrahydrate"
        ]
      ],
      "raw_glosses": [
        "(inorganic chemistry) The double salt potassium sodium tartrate tetrahydrate (KNaC₄H₄O₆·4H₂O), used for various scientific and medical purposes."
      ],
      "synonyms": [
        {
          "word": "Seignette salt"
        }
      ],
      "topics": [
        "chemistry",
        "inorganic-chemistry",
        "natural-sciences",
        "physical-sciences"
      ]
    }
  ],
  "word": "Rochelle salt"
}

{
  "etymology_text": "From La Rochelle in France.",
  "forms": [
    {
      "form": "Rochelle salts",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Rochelle salt (plural Rochelle salts)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "Quotation templates to be cleaned",
        "en:Inorganic compounds"
      ],
      "examples": [
        {
          "ref": "1998, Georgina Ferry, Dorothy Hodgkin: A Life:",
          "text": "In fact, at the current state of knowledge and technology, probably only the simplest of the structures she worked on in Cambridge, Rochelle salt, could have been fully solved at the time.",
          "type": "quote"
        }
      ],
      "glosses": [
        "The double salt potassium sodium tartrate tetrahydrate (KNaC₄H₄O₆·4H₂O), used for various scientific and medical purposes."
      ],
      "links": [
        [
          "inorganic chemistry",
          "inorganic chemistry"
        ],
        [
          "double salt",
          "double salt"
        ],
        [
          "potassium sodium tartrate tetrahydrate",
          "potassium sodium tartrate tetrahydrate"
        ]
      ],
      "raw_glosses": [
        "(inorganic chemistry) The double salt potassium sodium tartrate tetrahydrate (KNaC₄H₄O₆·4H₂O), used for various scientific and medical purposes."
      ],
      "topics": [
        "chemistry",
        "inorganic-chemistry",
        "natural-sciences",
        "physical-sciences"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "Seignette salt"
    }
  ],
  "word": "Rochelle salt"
}