Palm leaf was found to be four times as strong as good quality hand-made paper. Its loss of strength on accelerated ageing is slight but its folding endurance is nil. It is an excellent material for record from the permanence point of view, but its poor resistance to wear and tear makes it unsuitable for constant handling. Though thymol and paradichlorobenzene have practically no harmful effect on paper, fumigation with thymol of palm leaf manuscripts for seven days brings about 21.5 per cent loss in tensile strength while with paradichlorobenzene such loss is 11 per cent only which can be further reduced by paradichlorobenzene fumigation in the presence of water vapor to ensure at least 65 per cent relative humidity. This can easily be done by keeping in the fumigation chamber a trough containing a saturated solution of potassium dichromate. Paradichlorobenzene should therefore be considered as more suitable for the fumigation of palm leaves provided care is taken to avoid desiccation. High humidity keeps the flexibility of palm leaves but encourages the growth of insects and mildew and increases the tendency to 'blocking', i.e. the property of sheets or leaves to form one block under a certain pressure and temperature. Dry heat, the greatest enemy of palm leaves, on the other hand, makes them brittle like biscuits and causes the surface layers to burst into thin strips. Acidity is harmful to the preservation of palm leaves just as it is to all paper records, and this should be removed prior to repairing by immersion in a slightly alkaline solution.