From: Jed Rothwell
> Helium alone cannot leak IN without argon. Complete nonsense ! Helium has an enormous diffusion rate through Pyrex glass. Argon has almost none. Check the MIT site if you want a source. Even if Argon could diffuse in, which it cannot – Grahams Law would mean the rate of diffusion was much higher for helium. You statement is complete naïve. > I did not make this stiff up, as Dave Barry used to say. Apparently you do make it up… or else you do not understand Grahams Law at a very minimum. Jones