He thus enunciated the law of the expansion of gases, stated some months later by Gay-Lussac. In the two or three years following the reading of these essays, he published several papers on similar topics, that on the "Absorption of gases by water and other liquids" (1803), containing his "Law of partial pressures."
"packing" the towers have been rendered more durable, and in the case of the Gay-Lussac tower the loss of nitre has been diminished by avoiding the use of a coke packing, which acts upon that substance as a reducing agent.
This method was followed by that proposed by Gay-Lussac and Thenard, who decomposed molten caustic soda with red-hot iron; and this in turn was succeeded by Brunner's process of igniting sodium carbonate with charcoal.
But this elevation was not considered sufficient by Gay-Lussac, who therefore made a second ascent by himself on the 16th of September, when the balloon rose 7016 metres (about 23,000 ft.) above sea-level.
The hydrosulphide, KHS, was obtained by Gay-Lussac on heating the metal in sulphuretted hydrogen, and by Berzelius on acting with sulphuretted hydrogen on potassium carbonate at a dull red heat.