Rob Beynon's nice BufferStack is now available from the IuBio
archives via anonymous FTP: 
       >ftp iubio.bio.indiana.edu
      ftp> user anonymous  guest
      ftp> cd [archive.molbio.mac]
      ftp> get buffer.sit_hqx

Given the appropriate information, the BufferStack will construct 
a complete recipe for a buffer that is defined in terms of both 
pH and ionic strength, at the temperature of use.

The recipe will be based on the simplest method of preparing a 
buffer- by titration of a solution of acid or base to the correct 
pH. 

Author: Rob Beynon
        Proteolysis Research Group
        Department of Biochemistry
        University of Liverpool
        PO Box 147, Liverpool L69 3BX, UK
        (SB06@UK.AC.LIV.IBM)
        (or try SB06@IBM.LIV.AC.UK from USA nets)

See 
Beynon, R.J. (1988) "A Macintosh Hypercard stack for calculation 
of thermodynamically-corrected buffer recipes". CABIOS 4, 487-490