What was I? Such a clever friar

What was I ? Such a clever friar,
I barely 'scaped the witches' pyre ;
Yet doth philosophy in me
One of her bright admirers see ;
And forms of classic beauty grew
Beneath my hand to nature true ;
Each wondrous magic lantern show
To me the happy children owe ;
With Schwartz contesting, I should mention
The honour of his great invention.
What am I ? What you may despise,
For I am little more than grease,
And yet I am an annual prize
For matrimonial love and peace.

In every scrape or awkward plight
I hope to save me you'll be able.
I am the ploughboy's great delight,
And often grace his Sunday table.
From dreams of mire and sweet repose
To streaky excellence I rose ;
And, following still the chimney sweep,
I learned to smoke instead of sleep.