Alcohol distilleries. Historical artwork of two horse-drawn alcohol distilleries. They were used to concentrate the alcohol in drinks like brandy. The alcohol was heated above a boiler in the vessels at far left. Alcohol, a very volatile liquid, evaporates easily, forming a greater proportion of the vapour coming out of these vessels. This vapour is condensed in the other vessels by a cold liquid refrigerant. The resulting more concentrated alcohol can then be collected. For further purification the alcohol can be distilled again. This artwork is from a French book published in 1908.