Steam digester Torricelli and further developed by German scientist Otto von Guericke with his Magdeburg hemispheres. Guerike's demonstration was documented by Gaspar Schott, in a book that was read by Robert Boyle. Boyle and his assistant Robert Hooke improved Guericke's air pump design and built their own. From this, through various experiments, they formulated what is called Boyle's law, which states that the volume of a body of an ideal gas is inversely proportional to its pressure. Soon the ideal gas law was formulated. Based on these concepts in 1679 a Boyle's associate, named Denis Papin, built a "bone digester", which is
Volume (thermodynamics) without reference to an exact operating volume, which may not be known (nor significant) at some stages of analysis. The specific volume of a substance is equal to the reciprocal of its mass density. Specific volume may be expressed in formula_14, formula_15, formula_16, or formula_17 . where, formula_3 is the volume, formula_20 is the mass and formula_21 is the density of the material. For an ideal gas, where, formula_23 is the specific gas constant, formula_24 is the temperature and formula_25 is the pressure of the gas. Specific volume may also refer to molar volume. The volume of gas increases proportionally