the weight of as much water, as is equal in bulk to itself, that is, 2 grains, and as the gold weighs 38 grains, it follows, that the weight of water is to that of gold, bulk for bulk, as 2 to 38, that is, as the weight lost in the fluid is to the whole weight. And so, if a piece of gold, and a piece of copper, are equiponderant in air, yet in water the gold will outweigh the copper; because their bulks, tho' of equal weight, are inversely as their specific gravities, that is, the gold must be as much less than the copper, as the specific gravity of gold is greater than that of copper: And as they must both lose weight in proportion to bulk in water, therefore the gold, the lesser of the two, loses less of its weight than the copper does, and consequently, out-weighs the copper in water. I hope this is clear. The case is the same, in proportion, in pure gold, and gold mixed with other metals. The bulk of the pure gold must be less than that of allayed gold, and its weight greater in water; tho' both equiponderate (a pound suppose) in air. It is very plain, Sir, and I request you will proceed. You give me valuable information, and oblige me very much. This pleased the Chemist, and the ingenious little Ribble went on. As to the simplicity of gold, we mean, by a simple body, that whose minutest part has all the physical properties of the whole mass. Now dissolve a grain of gold in aqua regia, and from a single drop of the solution, a particle of gold may be separated, and have all the characters of gold, (except those of magnitude,) though the separated particle of gold shall only be the millionth part of the grain. —Or, fuse a single grain of gold with a mass of silver, and mix the whole together, so that the gold shall be equally distributed: then take a particle thereof, and you will have a particle of perfect gold; for dissolve the least part of the mixture in aqua fortis, and a quantity of gold will precipitate to the bottom. It will bear the same proportion to the grain, that the part dissolved did to the whole mass. Having mentioned aqua regia and aqua fortis, I must, to be intelligible, say two or three words in relation to them. Aqua regia is an extract by fire from sea-salt and spirit of