Jean Baptiste Dumas
July 16, 1800- 1884
Contributions to Science
Dumas' original contributions stemmed from the adaptation of existing ideas and not from the desire to make revolutionary breakthroughs. He investigated the mechanism involved in the formation of animal fat and attempted to establish that it was utilized in the maintenance of body heat and combustion while it formed a reserve, stored in the tissues of it's body, which could be used for metabolism when necessary. Dumas investigate problems in metallurgy, such as the preparation of calcium and the treatment of iron ores; he studied the nature and properties of different kinds of commercial glass, he also was interested in questions as diverse as the materials used in the thirteenth century frescoes, and the nature of the compounds of phosphorus.
Dumas Vapor Density
Jean-Baptiste Dumas invented a way of determining the molar mass of substances that can easily be turned into vapor. The Dumas method is still the subject of laboratory exercises in chemistry courses. It involves finding the mass, volume, temperature, and pressure of a substance in the vapor phase. The determination of molar mass in a modern Dumas method experiment uses the ideal gas law: knowing the pressure, volume, and temperature of a gas sample allows one to know the number of moles knowing the mass that corresponds to that number of moles allows computation of the molar mass.
The Theory of Substitutions
The theory of substitutions was said by Dumas in 1834. Its main idea was that hydrogen in any state could be replaced by the same amount of a halogen, oxygen, or other element. In order to explain the action of chlorine on a substance compound contains water. The hydrogen is destroyed without replacement; but if a further quantity of hydrogen in subsequently removed, then it is replaced by an equivalent amount of chlorine.