"fixed air" meaning in English

{
  "etymology_templates": [
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      "args": {
        "1": "en",
        "2": "Joseph Black",
        "in": "1756",
        "nat": "Scottish",
        "nobycat": "1",
        "occ": "chemist"
      },
      "expansion": "Coined by Scottish chemist Joseph Black in 1756",
      "name": "coin"
    }
  ],
  "etymology_text": "Coined by Scottish chemist Joseph Black in 1756 because it can be absorbed, or fixed, by strong bases.",
  "head_templates": [
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      "expansion": "fixed air (uncountable)",
      "name": "en-noun"
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
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        {
          "kind": "other",
          "name": "English entries with incorrect language header",
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            "Entries with incorrect language header",
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          "langcode": "en",
          "name": "Chemistry",
          "orig": "en:Chemistry",
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          "source": "w"
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      "examples": [
        {
          "ref": "1790, Edmund Burke, Reflections on the Revolution in France, Oxford, published 2009, page 8",
          "text": "The wild gas, the fixed air is plainly broke loose: but we ought to suspend our judgement until […] we see something deeper than the agitation of a troubled and disturbed surface.",
          "type": "quotation"
        },
        {
          "ref": "1997, Roy Porter, The Greatest Benefit to Mankind, Folio Society, published 2016, page 246",
          "text": "Lavoisier then elucidated the exchange of gases in the lungs: the air inhaled was converted into Black's fixed air, whereas the nitrogen (‘azote’) remained unchanged.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Carbon dioxide; carbonic acid."
      ],
      "id": "en-fixed_air-en-noun-wetHK2FN",
      "links": [
        [
          "chemistry",
          "chemistry"
        ],
        [
          "Carbon dioxide",
          "carbon dioxide"
        ],
        [
          "carbonic acid",
          "carbonic acid"
        ]
      ],
      "raw_glosses": [
        "(chemistry, now historical) Carbon dioxide; carbonic acid."
      ],
      "tags": [
        "historical",
        "uncountable"
      ],
      "topics": [
        "chemistry",
        "natural-sciences",
        "physical-sciences"
      ]
    }
  ],
  "word": "fixed air"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "Joseph Black",
        "in": "1756",
        "nat": "Scottish",
        "nobycat": "1",
        "occ": "chemist"
      },
      "expansion": "Coined by Scottish chemist Joseph Black in 1756",
      "name": "coin"
    }
  ],
  "etymology_text": "Coined by Scottish chemist Joseph Black in 1756 because it can be absorbed, or fixed, by strong bases.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "fixed air (uncountable)",
      "name": "en-noun"
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  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
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        "English coinages",
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        "English lemmas",
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        "en:Chemistry"
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      "examples": [
        {
          "ref": "1790, Edmund Burke, Reflections on the Revolution in France, Oxford, published 2009, page 8",
          "text": "The wild gas, the fixed air is plainly broke loose: but we ought to suspend our judgement until […] we see something deeper than the agitation of a troubled and disturbed surface.",
          "type": "quotation"
        },
        {
          "ref": "1997, Roy Porter, The Greatest Benefit to Mankind, Folio Society, published 2016, page 246",
          "text": "Lavoisier then elucidated the exchange of gases in the lungs: the air inhaled was converted into Black's fixed air, whereas the nitrogen (‘azote’) remained unchanged.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Carbon dioxide; carbonic acid."
      ],
      "links": [
        [
          "chemistry",
          "chemistry"
        ],
        [
          "Carbon dioxide",
          "carbon dioxide"
        ],
        [
          "carbonic acid",
          "carbonic acid"
        ]
      ],
      "raw_glosses": [
        "(chemistry, now historical) Carbon dioxide; carbonic acid."
      ],
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        "historical",
        "uncountable"
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      "topics": [
        "chemistry",
        "natural-sciences",
        "physical-sciences"
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  ],
  "word": "fixed air"
}