Giacinto Cestoni

Plaque dedicated to Diacinto Cestoni and Giovan Cosimo Bonomo for their scientific contributions.

Cestoni's had an interest in plants and herbs, analyzing drugs and their medicinal effects. The pharmacological aspect was extensively treated by Cestoni, who among other things was always very attentive to the different opinions on the use of medicines. As an apothecary he studied different contagious diseases and carried out treatment trials using different drugs.[5] The method followed by Cestoni for medicines was through trial and testing, and observing on their effectiveness. Since Cestoni was not a doctor he heavily relied on consulting his friend Redi for many of his medical trials.[6]

Evidence of his main pharmacological studies are found in his letters to Redi and other friends and colleagues. In these letters, Cestoni recorded observations of many plants including sarsaparilla and Cinchona.

Cestoni's research on cinchona was important at the time. He was able to devise a safe treating mechanism using cinchona which he shared with his friend Vallisnieri in letters. He made some recommendations regarding cinchona. Cestoni wrote about its effectiveness in powdered form and the dosage and methodology of consuming the drug.

In his correspondences with his friend, Cestoni also wrote about his observations and experiments with Sarsaparilla. Cestoni examined the sarsaparilla, a plant whose roots are used to make medicine, also historically used in treating syphilis. Cestoni was able to prepare a decoction and also provided information on the method and the exact dose of administration.[7]

Cestoni also studied the effects of foods and drinks such as chocolate, coffee and lemongrass. Cestoni believed that chocolate consumption should be balanced. He called it nutritious but bad for the stomach if consumed in large quantities. In his letters, Cestoni indicates that he did not consider chocolate a medicine, but a tasty food that's hard to digest and therefore whoever consumes it in small quantities will be healthy. He recommended health compromised individuals not to take it.

His main research area was observing insect reproduction, and through his observation with a microscope he eventually discovered the viviparity and parthenogenesis of aphids.

Among one of his letters sent to Vallisneri on August 19, 1697, he revealed that he had observed flea's eggs and that from these eggs "lactated white bacherelli" were born which, after two weeks, grew and made a silk thread come out of their mouth. which was used for the construction of the cocoon; the flea grew inside the cocoon and formed completely before exiting. He also observed other insect species including green grasshoppers, scorpions, woodworms, cabbage insects, worms and studied insect galls and discovered galls on oak trees were caused by flies.

He also studied the coral and his investigations on coral are found in a study made by G. De Toni. who stated in 1723 that Cestoni had asserted that the coral was nothing but "an insect similar to a small sea oyster or octopus."

Cestoni also studied seaweed, in particular the Posidonia oceanica. He proved that the seaweed possessed seeds and fruits like any other plant. Cestoni was the first to show flowers and fruits of the seaweed, and was the first who observed that sea balls were an aggregate of the fibers of the seaweed conglomerated by the sea waves.

Among microorganisms, Cestoni studied infusoria in water and also significantly studied vinegar eels (Anguillula vinegar), which are found in unfiltered vinegar.

In some of his letters addressed to Redi, Cestoni discussed with his friend about stones in the stomach of birds and grafts. He correctly deduced that the stones actually helped the birds in digestion. Cestoni experimented with grafting and attempted to transplant the spur of a chicken onto the head of a rooster.  

Title of Cestoni's published research on Chameleon and other animals.

Perhaps his most notable work was on the research he did on scabies. He collaborated with a physician from Livorno who was a disciple of Redi, Giovan Cosimo Bonomo. Cestoni and Bonomo described the life history of the itch mite, Sarcoptes Scabiei that causes scabies. Cestoni helped in discovering the link of the mite with scabies. He observed the mite under a microscope uncovering details about the mite's life history, means of infection, and effective vs ineffective treatments. These conclusions were controversial in his day, and opposed by prominent physicians such as Giovanni Maria Lancisi, the Pope's chief physician in Rome, since the established belief was that scabies was caused by an excess of black humour (melaina colè).[8] Cestoni shared his findings with Redi in one of his letters he sent in 1687.[9] Cestoni published six illustrations of the life cycle and discussed the means of transmission to new hosts. Cestoni also wrote to Vallisnieri in 1710 that he, not Bonomo, had discovered that scabies was caused by a mite.

Cestoni was interested in studying animals. He studied invertebrates such as arthropods, molluscs, worms and vertebrates. He studied eels, "vinegar eels", "worms" and caterpillars, barnacles, cockroaches, ship mists (lamellibranch mollusc known today as teredine), ants, earthworms, praying mantis, millipedes (myriapods), flies, oysters, fish, lice, bat, green lizard, frog, sea urchin, swallows, toads, salamander, scarab, scolopendra, "flying beetle", "water scorpion", sponges, woodworms, turtle, tapeworms, tarantulas, wasps, vipers, mosquito, ticks, zoophytes.

He significantly studied chameleons and his keen interest in it can be seen in the letters he exchanged with his friends. His work on chameleons was also published in his friend Vallisnieri's work "Istoria del Camaleonte affricano, e di varj animali d'Italia".

Through systematic direct observations he had managed to draw a precise picture of the animal's habits. He was able to disprove the myth at the time about chameleons that they do not eat and drink and just lived on air. He observed their eating habits and found out that they eat insects including crickets, grasshoppers, butterflies, spiders, white snails, lizards, winged ants. Though he spent a lot of time observing the chameleon he was not able to provide an explanation for the shift in its colors. Vallisneri's research on chameleons was significantly based on observations of Cestoni.[10]