‹‹‹ Vitr. 8.3.17 | Table of Contents | Vitr. 8.3.19 ›››
18This seems to arise from an acrid and acid moisture being under the earth, from which the waters acquire their acridity; and when introduced into the system, dissolve that with which they come in contact whether generated by deposition or concretion. That acids will have this effect, is clear, from the experiment on an egg, whose shell, when kept therein for some time, will be softened and dissolve. Lead, also, which is very flexible and heavy, if placed in a vessel and covered with acid, and there left open, will be dissolved, and become white lead.
18This seems to be due to natural causes, as there is a sharp and acid juice contained in the soil there, which imparts a sharpness to these springs as they issue from it; and so, on entering the body, they disperse all the deposits and concretions, due to the use of other waters, which they find in the body. Why such things are broken up by acid waters we can see from the following experiments. If an egg is left for some time in vinegar, its shell will soften and dissolve. Again, if a piece of lead, which is very flexible and heavy, is put in a vase and vinegar poured over it, and the vase covered and sealed up, the lead will be dissolved and turn into white lead.