Letter from Thomas Gold to Mr I Binsburgh, Amoco Oil Company Research and Development Department, PO Box 400, Naperville, Illinois Thanks him for the note in ' Oil and Gas '. He has plenty of figures form many deep sources, and there is a wide range of values - as in meteorites. States nothing much can be decided. The H-D ratio is interesting and in the right sense - less D for deep gas. 13 February 1979