The microscope from Galileo to the Accademia del Cimento
In Il Saggiatore [The Assayer] (Rome, 1623), the Pisan scientist mentioned a “telescope modified to see objects very close”. In 1625 a member of the Accademia dei Lincei and friend of Galileo, Johannes Faber (1574-1629) conferred on the instrument, until then called “occhialino”, “cannoncino”, “perspicillo”, and “occhiale”, the name of “microscope”.
The first microscopes of the Galilean type had, like the telescope, a concave lens and a convex one mounted in a rigid tube. Thanks to these simple optical devices the philosophers of nature could now gaze on a new and marvelous world, which was later to allow the development of both medical-biological disciplines and naturalist ones.
The fame of Galileo's optical instruments inspired a search for new solutions. In the 1620s, microscopes of the Keplerian type, composed of convex lenses that furnished a reversed image, were developed.
However, some details of his drawings suggest that he owned more powerful ones, with which he could observe, starting from 1677, red blood cells, spermatozoids, rotifers, and bacteria.
Even his compatriot Jan van Musschenbroek (1687-1748), for entomological research, used a simple microscope mounted on an articulated arm that proved extremely effective. Adopted by Abraham Trembley (1710-1784), it established itself as the "aquatic" microscope of choice for observing flora and fauna from the outside of a glass vessel.
In 1740 Trembley, using this type of microscope, observed the particular behavior of the “freshwater polyp” or hydra, noting also its surprising ability to regenerate parts that had been amputated.
The next development in the simple microscope was Pieter Lyonnet's (1708-1789) "anatomical tablet", used, among others, by Lazzaro Spallanzani (1729-1799) for minute dissections. However, for entomological research, the Italian naturalist probably used the microscope designed by James Wilson (1655-1730) and built by John Cuff (c.1708-1772) c. 1742, also called "portable" or "pocket" microscope. A compound microscope only in appearance, this model enabled — among other things — Spallanzani in 1773 to discover tardigrades and their ability to experience repeated death/revival cycles.
The phenomenon, now called anabiosis, marked one of the major turning points of 18th-C. theoretical biology.
Microscopic anatomy was however developed in all of its potentiality by Marcello Malpighi (1628-1694). As Galileo had launched exploration of the great machine of the universe with the telescope, so Malpighi aimed to reveal the hidden structure of the machine that was the human body with the microscope.
He observed the alveolar structure of the lungs, the papillary receptors on the tongue, the connection between arterial and venous blood vessels, identified the red blood cells and described precisely the first stages in the embryonic development of a baby chick.
The combination of “thin” anatomy and microscopic magnification soon led to a succession of remarkable discoveries.
Thomas Bartholin (1616-1680) identified the lymphatic ducts; Lorenzo Bellini (1643-1704) revealed the structure and function of the kidneys, furnishing an explanation of the mechanical type; Thomas Wharton (1614-1673) formulated the theory of the glands as secretory organs; Niels Steensen (1638-1686) conducted accurate microscopic observations of muscle fibers.
Francesco Redi (1626-1697) illustrated the extraordinarily complex organization of insect life;Thomas Willis (1621-1675) and then Albrecht von Haller (1708-1777) studied the structure of the nervous system and the dynamics of neuro-muscular functions.
Curator: Sara Bonechi