^{page 1 note *} An account of these experiments was announced for publication in 1819, in the 1st Number of the Edinburgh Philosophical Journal; but the desire of obtaining more general results prevented me from publishing it at that time.

^{page 3 note *} Philosophical Transactions, 1822, p. 367.

^{page 11 note *} In a specimen of Topaz which split in the fire, I found that a quantity of the new fluid had got into a fissure, where it has been permanently detained without reaching the surface. It exhibits the same brown tint as the globules, at particular inclinations.

^{page 12 note *} A full account of these experiments will be found in the Philosophical Transactions for 1816, p. 73.

^{page 21 note *} In Figs. 20. and 21. there are small squares, such as S, S, within the cavities, which seem to be filled up with crystallized matter. These squares being sometimes united only by contact with the surface of the cavity, exhibit very brilliantly the colours of thin plates.

^{page 22 note *} This crystal is the one referred to in page 11.

^{page 27 note *} A round hemispherical drop often stretches itself into a plane of more than twelve times its original area.

^{page 29 note *} In opened specimens, which had stood more than a month exposed to the air, I observed small green spheres resting on the surface. They were soft and semitransparent, like green wax, and varied from to of an inch in diameter. They were not acted upon by any of the above mentioned acids, and were therefore a distinct substance from that of the two new fluids. They occurred in no fewer than 25 out of 40 crystals, three being sometimes found in one specimen; and there can be no doubt that they consisted of fluid matter which had oozed out of the crevices of the mineral.

^{page 29 note †} There were also numerous opaque particles in the cavity, which descended slowly in the fluid.

^{page 31 note *} Since these observations were made, Mr Nordenskjold has confirmed this result by experiments made with the blowpipe.

^{page 38 note *} See the Edinburgh Philosophical Journal, vol. iii. p. 98., for an account of the polarising structure which sometimes exists round the cavities in diamond.

^{page 38 note †} This point may be easily determined by grinding the specimens, and examining the light reflected at the surfaces of the cavities.

^{page 39 note *} As the effects of heat and compression might exactly balance each other, the gas would in this case be atmospheric air, in a common state of density; so that the volcanists are here sheltered against experimental hostilities, amid the generalities of their hypothesis.