Pneumatic chemistry developed in the eighteenth century with the work of scientists such as Stephen Hales, Joseph Black, Joseph Priestley, and Antoine-Laurent Lavoisier, and others. Until the eighteenth century, gas was not recognized as a separate state of matter. Rather, while some of the mechanical properties of gases were understood, as typified by Robert Boyle’s experiments and the development of the air pump, their chemical properties were not. Gases were regarded in keeping the Aristotelean tradition of four elements as being air, one of the four fundamental elements. The different sorts of airs, such as putrid airs or inflammable air, were looked upon as atmospheric air with some impurities, much like muddied water.
Philippe LeBon was a French civil engineer working in the public engineering corps who became interested while at university in distillation as an industrial process for the manufacturing of materials such as tar and oil. He graduated from the engineering school in 1789, and was assigned to Angoulême. There, he investigated distillation, and became aware that the gas produced in the distillation of wood and coal could be useful for lighting, heating, and as an energy source in engines.
He took out a patent for distillation processes in 1794, and continued his research, eventually designing a distillation oven known as the thermolamp. He applied for and received a patent for this invention in 1799, with an addition in 1801. He launched a marketing campaign in Paris in 1801 by printing a pamphlet and renting a house where he put on public demonstrations with his apparatus. His goal was to raise sufficient funds from investors to launch a company, but he failed to attract this sort of interest, either from the French state or from private sources.
Although the thermolamp received some interest in France, in Germany interest was the greatest. A number of books and articles were written on the subject in the period 1802–1812. There were also thermolamps designed and built in Germany, the most important of which were by Zachaus Winzler, an Austrian chemist who ran a saltpetre factory in Blansko. Under the patronage of the aristocratic zu Salm family, he built a large one in Brno. He moved to Vienna to further his work. The thermolamp, however, was used primarily for making charcoal and not for the production of gases.