Note 72 — Chapter I · ON WATER AND ITS COMPOUNDS
George Kamensky translation
The diagram given in note 28 shows the evolution of heat on the mixture of sulphuric acid, or monohydrate (H2SO4, i.e. SO3 + H2O), with different quantities of water per 100 vols. of the resultant solution. Every 98 grams of sulphuric acid (H2SO4) evolve, on the addition of 18 grams of water, 6,379 units of heat; with twice or three times the quantity of water 9,418 and 11,137 units of heat, and with an infinitely large quantity of water 17,860 units of heat, according to the determinations of Thomsen. He also showed that when H2SO4 is formed from SO3 (= 80) and H2O (= 18), 21,308 units of heat are evolved per 98 parts by weight of the resultant sulphuric acid.