The chemistry and use of mannitol are briefly discussed. Once again in a conservation paper EDTA is introduced without giving its proper chemical name. The results of an experiment where seven samples of waterlogged wood were treated by soaking in solutions of mannitol or polyethylene glycol (PEG) prior to freeze-drying are given. These results suggest that mannitol may be a more successful treatment that PEG. Several objects treated with mannitol and PEG were reassessed six months after treatment. The results of the treatments were similar. The process using mannitol is described.