Ask the Scholar

{
    "localId": "75720556",
    "label": "Report to [A. Roeder], January 28, 1926",
    "core": "doc",
    "dtoType": "document",
    "citationUrl": "https://catalog.archives.gov/id/75720556"
}

{
    "id": "75720556",
    "sourceUrl": "https://catalog.archives.gov/id/75720556",
    "contentType": "document",
    "title": "Report to [A. Roeder], January 28, 1926",
    "citationUrl": "https://catalog.archives.gov/id/75720556",
    "collections": [
        "Safety Light Collection",
        "Records Related to Radium Dial Painters"
    ],
    "iiifBase": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0000695_Page_01.jpg",
    "thumbnailUrl": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0000695_Page_01.jpg",
    "largeImageUrl": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0000695_Page_01.jpg",
    "imageCount": 24,
    "hasImages": true,
    "source": "import",
    "hasTranscription": false
}

{
    "url": "https://catalog.archives.gov/id/75720556",
    "naId": 75720556,
    "levelOfDescription": "fileUnit",
    "recordType": "description",
    "ocrSource": "nara-archive"
}

{
    "seq": 23,
    "pageIndex": 0,
    "type": "photo",
    "url": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0000695_Page_23.jpg",
    "mediaId": "c8c5d8ae62de7864",
    "ocrText": "I9.\nposed effect betweox Roentgan rays and thorium X. T 9 later exerts directly only a\nalight effect ion the clymphoid tissue. The myeloid tissue ox the contrary is earlier\nand more intensely injured.\nIn considering the effect of Mesothorium and radium we must bear in mind eer=\ntain faots. Mesothorium decays 250 times as fast s.a radium does, and consequemtly in\nits pure state, weight for weight, its activity would greatly exceed that of radium.\nBut in these paints the quantity of mesothorium is not expressed in milligrams by\nweight but its equivalemt in radium. Therefore the activity of the two compounds com-\npared bear the same ratio as the values assigned to the preparation.\nAlthough meso thorium gives off no rays, its first decomposition product after\nmesothorium has been separated gives off powerful beta and gamma rays. For this rea-\nson the operator must protect himmelf against these rays. On the other hand in the pro-\nduction of radium, the product giving the penetrating gamma rays (RaC) is formed rather\nslowly.\nIn studying the possible effect of mesothorium that may become deposited in the\nthat\nbody one must bear in mind the fact the have period of radium ia I580 years while that\nof mesothorium is 6.7 years. In the decay of radium we first have an qmanation having\na half period of 3.8 days. This is followed by the active deposit of rapid change ( RaA,\nRaB,\nRaC ) followed by an active deposit of slow change RaD, RaE, RaF. Radium D and\nE emit soft bets rays and have a half period of I6.5 years and 4.85 days respectively.\nRadium F or polonium emits alpha rays and has a. half period of 136.5 days. But in the\ncase of mesothorium the emanations have a. half period of only 54.5 seconds. which is\nfollowed by thorium A,B, and C which are comparable to the same series of radium. Thor-\nium c is followed by In orium D ( Th lead ) which is stable. We have similar product\namount\nand\namilar\nin the thorium decomposition products to radon of the radium products which has a com-\nparatively long live emitting alpha radiations. In' maximum range of an alpha particle\nfrom the thorium series is 8.6, while the for the radium series it is 6.94 cm."
}