The cloth of which the balloon-case was made was then cleaned by means of soda and potash, obtained by the incineration of plants, in such a way that the cotton, having got rid of the varnish, resumed its natural softness and elasticity; then, exposed to the action of the atmosphere, it soon became perfectly white.
Les toiles qui composaient l'enveloppe de l'aérostat furent ensuite dégraissées au moyen de soude et de potasse obtenues par incinération de plantes, de telle sorte que le coton, débarrassé du vernis, reprit sa souplesse et son élasticité naturelles; puis, soumis à l'action décolorante de l'atmosphère, il acquit une blancheur parfaite.