ENGRAVING ON EGGS.—The art of engraving on eggs is very puzzling to the uninitiated, but in reality it is very simple. It merely consists in writing upon the egg-shell with wax or varnish, or simply with tallow, and then immersing the egg in some weak acid, such, for example, as vinegar, dilute hydrochloric acid, or etching liquor. Wherever the varnish or wax has not protected the shell, the lime of the latter is decomposed and dissolved in the acid, and the writing or drawing remains in relief. In connection with this art a curious incident is told in history. In the month of August, 1808, at the time of the Spanish war, there was found in a church in Lisbon an egg, on which was plainly foretold the utter destruction of the French, who then had control of the city. The story of the wonderful prophecy spread through the town, causing the greatest excitement among the superstitious populace, and a general uprising was expected. This, however, the French commander cleverly thwarted by causing a counter-prophecy, directly denying the first, to be engrossed on several hundred eggs, which were then distributed in various parts of the city. The astonished Portuguese did not know what to think of this new phenomenon, but its “numerousness,” if we may so call it, caused it to altogether outweigh the influence of the first prediction, and there were no further symptoms of revolt against the French.