He supported himself by teaching Latin at Lissa, and it was here that he published his Pansophiae prodromus (1630), a work on education, and his Janua linguarum reserata (1631), the latter of which gained for him a widespread reputation, being produced in twelve European languages, and also in Arabic, Persian and Turkish.
They include Ars Magnesia (1631); Magnes, sive de arte magnetica opus tripartitum (1641); and Magneticum naturae regnum (1667); Prodromus Coptus (1636); Lingua Aegyptiaca restituta (1643); Obeliscus Pamphilius (1650); and Oedipus Aegyptiacus, hoc est universalis doctrinae hieroglyphicae instauratio (1652-1655) - works which may claim the merit of having first called attention to Egyptian hieroglyphics; Ars magna lucis et umbrae in mundo (1645-1646); Musurgia universalis, sive ars magna consoni et dissoni (1650); Polygraphia, seu artificium linguarum quo cum omnibus mundi populis poterit quis respondere (1663); Mundus subterraneus, quo subterrestris mundi opificium, universae denique naturae divitiae, abditorum effectuum causae demonstrantur (1665-1678); China illustrata (1667); Ars magna sciendi (1669); and Latium (1669), a work which may still be consulted with advantage.
Of a very different kind is the next we have to notice, the Prodromus systematis mammalium et avium of Illiger, published at Berlin in 1811, which must in its day have been a valuable little manual, and on many points it may now be consulted to advantage - the characters of the genera being admirably given, and good explanatory lists of the technical terms of ornithology furnished.
For Orthoptera generally, see C. Brunner von Wattenwyl, Prodromus der europciischen Orthopteren (Leipzig, 1882), and Ann.
He notes with exultation the 9th of July 1595, as the date of the pseudodiscovery, the publication of which in Prodromus Dissertationum Cosmographicarum seu Mysterium Cosmographicum (Tubingen, 1596) procured him much fame, and a friendly correspondence with the two most eminent astronomers of the time, Tycho Brahe and Galileo.
Then, there are the Prodromus whales of old Scotch Sibbald, and Jonah's whale, as depicted in the prints of old Bibles and the cuts of old primers.
According to the Prodromus florae hispanicae of Willkomm and Lange (completed in 1880), the number of species of vascular plants then ascertained to exist in the country was 5096.
The publication of his Prodromus Florae Novae Hollandiae (in 1810), according to the natural method, led the way to the adoption of that method in the -universities and schools of Britain.
Coming to British Indian possessions, and beginning with Ceylon, we have Kelaart's Prodromus faunae Zeylanicae (8vo, 1852), and Ceylon.
In 1734 he also published Prodromus philosophiae ratiocinantis de infinito et causa finali creationis, which treats of the relation of the finite to the infinite, and of the soul to the body, seeking to establish a nexus in each case as a means of overcoming the difficulty of their relation.