Which preposition to use with predicables

of Occurrences 5%

I rather designed to direct your attention to the inquiry whether these attributes are, in fact, rightly predicable of Butterflies.

on Occurrences 1%

Under the present system, it needs no argument to show that the Non-slaveholding States, with a free population considerably more than double that of the Slave-holding States, and with much more generally distributed wealth and opportunities of spending, pay far more than the proportion predicable on mere preponderance in numbers of the expenses of a government supported mainly by a tariff on importations.

Which preposition to use with  predicables