Origin of elements

Abstract

WE believe the recent report in Nature1 under this title to be misleading in the light of recent observations. The recent measurement 2 of a=12C/13C=75 (+25, -15) for the ζ Oph cloud is interesting but not surprising because it can be regarded as a confirmation of earlier work3, as pointed out in ref. 1, and the conclusion that the relative abundance of 13C in the ζ Oph cloud seems to be terrestrial is quite straightforward. It would be an unwarranted assumption to extrapolate the results from ζ Oph (and other tenuous clouds) to the dense, dusty regions of both the galactic centre and the Orion Nebula. © 1973 Nature Publishing Group.