To the most honourable the Marquiss of Rockingham.

I Have taken the liberty of addressing the inclosed paper to your Lordship, as it contains a few observations on a subject not unknown to you, and may probably be thought of general use.

I have a further reason for addressing it to your Lordship, as it gives me an opportunity of expressing, in some small degree, the high sense of gratitude I bear your Lordship, for many and repeated favours and obligations conferred on,