Paris, France Folder C/parisC187

Previous | Home | Next

The classic Tschirnhausen experiments included diamonds, showing they could combust; and a mixture of minium (Pb3O4) and charcoal while measuring the amount of elastic fluid (carbon dioxide) that was produced as the elemental lead was regenerated. These experiments gathered large crowds of curious onlookers. These experiments helped to contribute to Lavoisier's understanding that the reaction of air accounted for the increase of weight of all substances burned or calcined. In this rendition of the great burning lens, the large lens to the left was made by placing together two pieces of glass filled with spirit of wine (ethyl alcohol); the diameter was about 1.2 meters. A second intermediate lens concentrated the suns rays even more. The operator wore dark glasses to avoided being blinded by the glare in the reaction vessel. Courtesy, The Robinson Library.