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and mathematical science," and one of the most illustrious Professors in 

 Bologna (J. Senebier). Vallisnieri, Professor of Natural History, 

 Padua, advised him to study natural history, and his father con- 

 sented to his following the bent of his own inclinations. 



From 1754 to 1760 he was Professor of Logic, Mathematics, and 

 Greek at Reggio in Lombardy, and then of Natural History in 

 Modena, where he remained until 1768, when he accepted the corre- 

 sponding Chair in Pavia, where he died in 1799 ; his physician was the 

 illustrious Scarpa. He journeyed much, and collected much, for he was 

 essentially a great naturalist of the widest sympathies. In 1765 he 

 published his Saggio di Osserv. microscop. concern, il systema di Needham 

 e Buffon, in which he established the animal nature of animalcula?, and 

 their development from pre-existing parents; and showed that there was 

 no such thing as a spontaneous generation of these creatures. His re- 

 markable work, Sopra le riproduzioni animali, surprised the scientific 

 world. He proved that reproduction of lost parts in animals the head 

 in snails, limbs in newts, &c. could take place to an extent hitherto 

 unacknowledged. He also made some remarkable observations on the 

 circulation of the blood, incited thereto by reading the works of Haller. 



In his Opuscoli difaica anim. e vegetabile (Modena 1776), he deals 

 with the problems of generation already mentioned. It is in his- 

 Dissertazioni difisica animate e tegetabile (1783) that he deals with 

 the problems of digestion. He started where Borelli and Reaumur 

 left off, using metal tubes, which he introduced into the stomachs of 

 animals, carnivorous or otherwise. He also experimented on him- 

 self by swallowing meat or bread, wrapped up in linen. He obtained 

 gastric juice and studied its effects in vitro, keeping the juice warm 

 and placing in it bread, meat, grains, and observing the effects of 

 artificial digestion. He used water added to the meat or bread as a 

 control test. He found that this juice dissolved flesh, bones, bread ; 

 that some parts were more readily dissolved than others. There was, 

 moreover, no putrefaction. Indeed, when opening a snake several 

 days after it had fed, he got no trace of putrefaction in the still un- 

 consumed cadaver in the stomach. 



As to the cause of the solution, the absence of signs of putre- 

 faction showed that it could not be due to this process ; in fact,. 

 putridity in meat was arrested or set aside by action of " the some- 

 thing " he used and regarded as gastric juice. He knew that the juice 

 coagulated milk, but as yet there was no proof of the acidity of the 

 juice, far less of its acidity being due to a mineral acid. That dis- 

 covery was reserved for W. Prout (1824). There is an excellent 

 English translation by one " who chooses to conceal his name." In 

 the introduction Spallanzani states that : 



" In the course of my public demonstrations in the year 1777, I repeated in the 

 presence of my hearers those celebrated experiments of the Academy of Cimento, i.?., 



Q 



