exsisto

Nam si obscurior et quasi caliginosa stella extiterit, pingue et concretum esse caeium, ut eius asspiratio gravis et pestilens futura sit; sin illustris et perlucida stella apparuerit, significari caelum esse tenue purumque et propterea salubre.

‘For if the star rises dim and, as it were enveloped in a fog, this indicates a thick and heavy atmosphere, which will give off very unwholesome vapours; but if the star appears clear and brilliant, this is a sign that the atmosphere is light and pure and, as a consequence, will be conducive to good health.’