Note on the association of helium and thorium in minerals

• Published in: Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1907
• Subjects: Greenland; Thomsen
• Online Access: http://dx.doi.org/10.1098/rspa.1907.0074; https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1907.0074

The question has been often raised of whether or not helium is a product of thorium radio-activity. My own view throughout has been that it is. Mr. Boltwood has recently argued that the helium in radio-active minerals may always be attributed to the action of the uranium-radium series of transformations. I wish in the present note to draw attention to a case where that view is clearly untenable. Prof. Julius Thomsen, of Copenhagen, described, in 1898, a helium mineral from Ivitgut, Greenland, similar in some respects to fluor spar, but containing rare earths. Recently he has determined the quantity of helium liberated on heating as 27 c. c. per kilogramme.