Antonio Vallisneri Senior and the Earth Sciences
At the beginning of the eighteenth century the debate regarding the nature of fossils was slowly moving beyond the Aristotelian theory that fossils were of inorganic origin, and towards the theory of an organic genesis. Supporters of the theory of the organic genesis of fossils affirmed initially that they were a consequence of the Universal Flood.
Even though many scholars from previous centuries such as Leonardo da Vinci (1425-1519), Girolamo Fracastoro (1478?-1553) and Bernard Palissy (1510-1583) had had correct intuitions regarding the exact origin of the so-called 'figured stones' (lapides figuratae), many scientists of the age accepted the biblical story of the Universal Flood as a scientific explanation: the fossils were the remains of organisms (corals, shells, sea-urchins, sharks) which had lived in other ages and had been in some way dragged to and left on mountains by the waters of the Flood.
During the eighteenth century many authors, among which Vallisneri, began to confute the Flood theory. For example, in his book Dei corpi marini che sui monti si trovano (Marine bodies found on the mountains), printed in 1728, he showed the nature of fossil shells and correctly maintained that they were the remains of organisms that had lived in other ages but which had nothing to do with the Universal Flood. Vallisneri was part of the group of scientists who were ready to welcome hypotheses that ignored the Flood and studied the history of the Earth solely on the basis of naturalistic observation.
In 1714, in his famous Lezione accademica intorno l'origine delle fontane (An academic lesson on the origin of fountains), held on 24 June in the Accademia dei Ricovrati (today the Galilean Academy of the Sciences, Letters and Arts) Vallisneri, basing his conclusions on direct observation of the phenomena, demonstrated the perennial cycle of water, attributing the origin of spring waters to rain. This was in contrast to the belief held by many that the origin, according to alembic theory, was seawater, which penetrated deep into the Earth, then evaporated among rocks due to the internal heat of the Earth, and then condensed in caves. Vallisneri pointed out that water flows from the vaults or sides of natural cavities and not from the ground. Furthermore, he demonstrated that in many cases there is a relationship between the quantity of precipitation and the discharge of springs. This dissertation was then published in 1715.
Many other observations that he made in the field of geology are also very interesting such as those regarding the salse di Sassuolo (Modena) (methane-rich brine seeps of Sassuolo) where he went to see for himself the source of the so-called stone oil or petroleum; the springs of fresh water under the sea in the gulf of La Spezia; the Pliocene sediments found on the Adriatic coast; and many other topics regarding soil, the erosion or retreat of the sea and the formation of flood plains. Furthermore, he wrote Notizie Intorno varie Acque Termali e in primo luogo delle famose de' Colli Euganei (Information regarding various thermal waters and in particular the famous ones in the Euganean Hills) in which he presented his own observations and thermometric proof which led him to distinguish waters with different temperatures and different degrees of salinity.
His spirit of curiosity also led him to collect a large number of rocks and fossils which, together with other natural objects, made up his museum. These objects, as his son wrote in the introduction to the 1733 edition of his father's works, were collected during his many trips from which he returned with "many rare productions of Nature, and of Art, either received as gifts from friends, or bought, or gathered with his own hands". Among the friends who gave him fossils, the Marquis Scipione Maffei, from Verona, can be remembered for his gift of a series of fossil fish from Bolca, some of which are exhibited here.
The first written documentation of the fossil deposits in Bolca (Verona), or rather the Pesciara di Bolca, dates back to 1555. Vallisneri was familiar with these deposits: in a letter dated 1716, from Sebastiano Rotari, there is a detailed description of the quarry; in another letter, Luigi Ferdinando Marsili responds to Vallisneri, providing information regarding the deposits.
Antonio Vallisneri Junior and the Earth Sciences
Antonio Vallisneri had the merit to donate his father's collections to the University of Padova, which placed them in the Palazzo del Bo. Following this donation, the chair Ad descriptionem et ostensionem ceterorum Simplicium was established in 1734 and entrusted to him. During the 1759-1760 academic year this chair became a three-year course under the name Ad Naturalem Historiam and included Mineralogy and Geology as well, thus establishing the entrance of the Earth Sciences into the academic world. The naturalistic theories of some of the most important geologists and palaeontologists of the eighteenth century were developed during these years.
One of these was Anton Lazzaro Moro (1687-1764), and his 1740 treatise De' Crostacei e degli altri marini corpi che si truovano su' monti (Crustaceans and other marine bodies found on the mountains) in which he tried to reconcile the biblical story of the Earth's history and geological and biological findings. He helped move beyond the biblical theories by claiming that fossils were found petrified inside rocks because they had grown in sea water before the mountains had risen above the sea level. Giovanni Arduino (1714-1795) was another geologist and is considered the father of modern stratigraphic geology.
He and Vallisneri Junior were friends and corresponded frequently. In a letter dated 30 March 1759 Arduino proposes a classification of the history of the Earth according to four "orders": Primary, Secondary, Tertiary and Quaternary, which correspond to the four geological eras used today. In this context of exchange and sharing of ideas, Vallisneri Junior continued to increase the number of objects in the collections, such as when he bought some minerals and plants from Mr. Stayt, owner of an old curiosity shop, in 1758. In 1759 he received some fossil shells from the Vicenza area, an encrusted human skull (on display in this exhibition) and elephant bones and teeth from the son of Giovanni Girolamo Zannichelli, a well-known Venetian pharmacist.
After the death of Antonio Vallisneri Junior, only the custodian Giovanni Fabris took care of the collections. The collections were then divided as various parts were assigned to the new subjects that were being created from the splitting up of the old ones. As far as the Museum of Geology and Paleontology is concerned, it has been difficult to trace the original objects belonging to the Vallisneri Museum since they were neither numbered nor catalogued. In 1869 Giovanni Omboni became the director of the Cabinet of Geology and Mineralogy. He found the collection in disorder and began to reorder and catalogue the extant objects. The result is the five volumes of manuscripts called the Collezione Catullo, in honor of his predecessor the naturalist Tomaso Antonio Catullo, which catalogue about 10,000 pieces. Only in rare cases has it been possible to identify which of these objects were originally part of the Vallisneri Museum.
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