Carlo Alfonso Guadagni - Specimen experimentorum naturalium quae singulis annis in illustri Pisano Lyceo. - 1779

Quarto: 198 pages with nine folding plates. This is the second much augmented edition, bound in contemporary carta rusticana.

Carlo Alfonso Guadagni (1722‑1801), a prominent Italian physicist and physician at Pisa, published Specimen experimentorum naturalium in 1779 as a large collection of over two hundred experiments in natural philosophy. The title indicates that these are experiments “which are shown each year in the illustrious Pisa Lyceum,” meaning they were part of an annual routine of experimental demonstrations at the University of Pisa.

Guadagni’s purpose was pedagogical: the collection functioned as a companion to his public demonstrations, enforcing the importance of empirical observation, the consistency of results, and engagement with experimental physics in education.

There is lots of interest here, including

Experiment on sound in a vacuum
One experiment described involves a tintinnabulum (a kind of small bell) hung by a thread inside a glass globe, which is then evacuated (air pumped out to produce a partial vacuum). The question Guadagni investigates is whether the sound of the bell can still be heard, and whether the tone changes, or if it is entirely suppressed. This is a standard demonstration in classical physics: the propagation of sound requires a medium (air or other), and in a vacuum sound is greatly diminished or lost. This experiment illustrates the nature of sound transmission and is a striking way to show that air (or another medium) is necessary.

Precision and reproducibility of apparatus and method
Guadagni emphasizes experiments which test the consistency of instruments and repeatability of observations. For instance, his plates show detailed apparatus; he describes devices such as barometers (including a “portable barometer” in another letter) and their behavior under variable conditions of pressure or altitude. These are less dramatic than vacuum sound, perhaps, but very important in the context of 18th‑century experimental physics.

Experiments with air pressure, vacuums, and rarefied air
Several of the experiments revolve around manipulating air, creating partial vacuums, observing the effect of rarefied air on motion, sound, or other phenomena. This includes studying how sound behaves in thinner air, how objects move, or how air resistance or pressure affects behavior. These experiments tie into the mechanistic physics of the age: what role does the atmosphere play, how do pressure differences work, etc.

An excellent copy of a lovely book, untrimmed and with wide margins.