[wendy3]

in PREFACE TO A DICTIONARY OF THE ENGLISH LANGUAGE

and some still continue to be variously written, as authours differ in their care or skill: of these it was proper to enquire the true orthography

from what I have learnt, OF can always be traced and put to another place when used at the beginning of a sentence; so the above sentence can be rewritten as it was proper to enquire the true orthography of these

or words of which I have reason to doubt the existence

can be rewritten as or words which I have reason to doubt the existence of

Of the laborious and mercantile part of the people, the diction is in a great measure casual and mutable

can be written as the diction of the laborious and mercantile part of the people is in a great measure casual and mutable


however, in the sentence below,

Of many words it is difficult to say whether they were immediately received from the Latin or the French, since at the time when we had dominions in France, we had Latin service in our churches.

I don't know why Johnson used OF to start the sentence; his meaning is clear, and I would replace OF with FOR.

Could anyone solve my doubt?