On the state of water and aëriform matter in cavities found in certain crystals

After adverting to the interesting phenomena connected with certain crystalline products of the globe, and showing that the Huttonian theory more plausibly accounts for their formation than the Wernerian, Sir Humphry proceeds to offer additional arguments in its favour, deduced from his examination of the aëiform and liquid matter contained in certain siliceous stones. The fluid was in all cases found to be nearly pure water; and the elastic fluid was pure azote, existing always, however, in a state of considerable rarefaction; namely, from 12 to 18 times more rare than atmospheric air. In the only two cases in which the relation of the bulk of the water to that of the void space could be ascertained, it was nearly as 2 to 1. In the chalcedonies of basaltic rocks the gas was also azote, but it was 61 or 70 times more rare than atmospheric air, the quantity of water to that of void space being the same as in the rock crystal.