Interesting pamphlet on the preparation of saltpetre, a critical component of gunpowder, probably published by the French Commission of Gunpowder ("Régie des poudres et salpêtres"; see Le Normand) at the time of the French Revolution. Including parts on the necessary materials, the preparation of the materials, the evaporation and crystallization of saltpetre and instructions on the use of an hydrometer and the other tools necessary for the manufacturing process.
With the bookplate of Roland Voegeli. A bit browned, but otherwise a very good copy. Le Normand, l'Art du distillateur II, p 187; Martin & Walter IV/2, 7776; Neville Historical Chemical Library I, p. 681.