Can a solicitor's retaining lien be established?

Lord Esher M.R. wrote one of three judgments, each of which concluded that a solicitor's retaining lien could not be established. Lord Esher wrote as follows [p. 315]: It appears that some money was placed in the hands of the defendants, who are solicitors, for a particular purpose. So long as that purpose existed there was a trust imposed on them, and they were bound, if they accepted the money at all, to employ it or lay it out in the particular way indicated by the trust. ... It is admitted that, being trustees, no lien would attach in their favour, because the money was intrusted to them for a specific purpose. Brandao v. Barnett, 12 Cl. & F. 787, is conclusive on this point.