Adhering hemp to lime wood

We are restoring a canvas oil painting from 19th century. It's made
on two pieces of lime wood, united, stuck together with two pieces
of lath on the back side. On the front side, over the joining of
wood it was applied a piece of hemp, under the paint layer. The hemp
is unstuck from the wood. We tried to stick it back with fish glue
but it's not working. Can somebody tell us what else can we use?

Loredana Solonaru
Faculty of "Cultural Patrimony - Conservation and Restoration"
Iasi, Romania

                                  ***
                  Conservation DistList Instance 12:63
                 Distributed: Monday, February 1, 1999
                       Message Id: cdl-12-63-011
                                  ***