This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Experiments in paraffining corks, as a protection against the action of gased liquids, demonstrated the fact that the paraffine did not penetrate the cork, but merely coated the surface. A cork of fine quality was boiled in paraffine for a sufficient length of time, then cut open and placed under a glass magnifying it a hundred times. Not a particle of the paraffine had penetrated the cork, and under ordinary pressure of the hand the paraffine scaled off. We would advise, however, to paraffine all corks by dipping the neck of the bottle into melted paraffine before they are capped or tin foiled for export or storage, as it not only makes the cork air-tight and improves the stopper of a bottle and protects it, but more especially will it prevent any corrosive action of impure tin caps or tin foil on the corks, and in consequence on the gaseous and liquid contents of a bottle.
Fig. 278. - Specimens of Tin-foiled and Labeled Bottles.