CARTER LEDYARD & MILBURN LLP
                          2 WALL STREET
                       NEW YORK, NY 10005




                          June 30, 2008



The Bank of New York,
 as Trustee of FT 1778
101 Barclay Street
New York, New York 10286

Attention: Rosalia A. Koopman
           Managing Director

      Re:                  FT 1778

Ladies and Gentlemen:

     We  are  acting as special counsel with respect to New  York
tax  matters for the unit investment trust or trusts included  in
the series identified as FT 1778 (each, a "Trust"), which will be
established  under  a certain Standard Terms  and  Conditions  of
Trust dated December 9, 2003, and a related Trust Agreement dated
as  of  today  (collectively, the "Indenture") among First  Trust
Portfolios  L.P.,  as  Depositor (the "Depositor"),  First  Trust
Advisors  L.P.,  as  Evaluator, First  Trust  Advisors  L.P.,  as
Portfolio  Supervisor, FTP Services LLC, as FTPS  Unit  Servicing
Agent,  and  The  Bank  of New York as Trustee  (the  "Trustee").
Pursuant  to  the  terms of the Indenture,  units  of  fractional
undivided  interest in the Trust (the "Units") will be issued  in
the aggregate number set forth in the Indenture.

     We   have  examined  and  are  familiar  with  originals  or
certified   copies,  or  copies  otherwise  identified   to   our
satisfaction,  of such documents as we have deemed  necessary  or
appropriate  for  the purpose of this opinion.   In  giving  this
opinion,  we have relied upon the two opinions, each dated  today
and  addressed to the Trustee, of Chapman and Cutler LLP, counsel
for  the  Depositor, with respect to the factual assumptions  and
the  matters of law set forth therein.  We have assumed that  the
assets  of the Trust will consist exclusively of debt securities,
equity  securities  in entities classified  as  corporations  for
federal income tax purposes, or a combination thereof.

     Based  upon  the foregoing, we are of the opinion  that  the
Trust will not constitute an association taxable as a corporation
under  the  relevant tax laws of the State and City of New  York,
and   accordingly   will  not   be  subject   to   the  New  York
State franchise tax (New York State Consolidated Laws Chapter 60,
Article  9-A) or the New York City general corporation  tax  (New
York Administrative Code Title 11, Chapter 6, Subchapter 2).

     We  consent  to the filing of this opinion as an exhibit  to
the  Registration  Statement  (No.  333-151720)  filed  with  the
Securities   and   Exchange  Commission  with  respect   to   the
registration  of the sale of the Units and to the  references  to
our  name  in  such  Registration Statement and  the  preliminary
prospectus included therein.

                               Very truly yours,




                               CARTER LEDYARD & MILBURN LLP