An Eclipse produces a Wondrous Egg


Figura e Descrizione d’ un Uovo Mirabile, che ha l’ Effigie dell’ Eclissi del Sole Naturalmente improntata su la Superficie des Guscio.

Milan: Appresso Giuseppe Marelli, 1748


Quarto: 24.5 x 18.7 cm. [16] pp.


Modern boards. A very fine, bright, crisp copy with very broad margins. The illustration on the title is of a miraculous egg that, purportedly, bore the image of an eclipse of the sun on its shell. Woodcut ornaments at the foot of dedication and on final leaf, initial. Extremely rare. I have located only one four other copies worldwide: Columbia University, two in the BN Braidense (Milan), and another in the Biblioteca Marciana (Venice.)

A bizarre account of an egg, laid in Borgosesia, diocese of Novara, during a solar eclipse. The author, Sebastiano Rovida, a Novarese "doctor of philosophy and medicine", gives a detailed description of the egg and analyzes the possible causes of this small wonder.

He writes, "During the solar eclipse of July 25, 1748, a chicken laid an egg that had an image of the eclipse upon its shell. The image was not only visible, but could also be felt, as if it were sculpted in relief. The orb of the sun (which was in the shape of an ellipse) was impressed into the surface of the shell, and had a dark golden color, while the rays, or little flames, were a little brighter than the rest of the shell. The image of the moon that eclipses part of the sun was observable. Below the image of the sun and its rays was a little six-pointed star that I believe to be Venus."

Having interviewed all those who witnessed the phenomenon, Rovida reports that the hen, just prior to laying the egg, was agitated by a change in air pressure that preceded the eclipse. Running to and fro in its frightened state, it either looked up at the eclipse or saw it reflected in a puddle, and horrified by what it saw, ran into the hen house, sat upon her nest, and laid the egg. The author speculates that the sight of the eclipse left such an impression on the mind of the panicked hen that the image was somehow communicated physically from the hen's brain to the egg, much in the way that (so he believed) birthmarks appear on the skin.

Rovida notes that even in humans strong emotional and physical reactions may be passed from mothers to their offspring (aversions to certain foods, for instance). Yet, he argues, that such transference can only happen if the mother has an actual sensorial experience; merely fantasizing about or imagining a phenomenon, regardless of how strong the emotional response it provokes might be, will not produce this effect. Vision is the most powerful sense by which such transference can be triggered. The image that causes the powerful emotional response is imprinted upon the retina of the viewer. It then activates the "animal spirits" and makes its way to the brain. From there, the impression is conveyed by the veins, lymphatic system, and nerves, and from there, to the fetus, all with lightning speed.

Anticipating the question of how such impressions could penetrate the hard shell of the egg, Rovida points to the elliptical shape of the sun's orb on the shell, which should be a perfect circle. This suggests to Rovida that the shell of the egg was still soft and malleable while in the hen, and that the membrane of the vagina molded the image upon it. Alternatively, he writes, the yolk could have produced the effect.

Perhaps sensing the outlandishness of his theories, Rovida doubles down with even more bizarre pronouncements. There is no region in Italy or any other country, he claims, where one cannot find a person upon whose face or body there is a mark "imprinted by the imagination" of his or her mother, including images of "fruit, milk, wine… or of the monstrous features of a dog or a cat or of another strange animal, copied due to the pregnant mother's strong affinity for or aversion to that animal."

Moreover, he speculates that the bizarre patterns and colors of wild beasts brought from Africa are the results of a compounding of this process. This great variety of beasts, gathering at the same watering hole, make such impressions upon one another that, upon returning to the darkness of their dens, the memories of what they had seen are made more vivid, and novel patterns are passed on to their offspring. Rovida also points to the example of rabbits in the Alps who, having snow constantly before their eyes, give birth to white offspring.

In a postscript, Rovida writes that since penning his account he has had confirmation that there was a great drop in barometric pressure on the day of the eclipse and, moreover, that he has had a report of two other eggs, laid on the day of the eclipse in Balmuccia, with similar eclipse images on their shells.

We know from an unpublished letter, written by the recipient of Rovida's report, that the egg was later given to the King of Sardinia.