Statistics for occurrence #1 of “Venus” in book 4, card 1235 of Lucretius, De Rerum Natura:
...throws the furrow, and from proper places
Deflects the spurt of seed. And courtesans
Are thuswise wont to move for their own ends,
To keep from pregnancy and lying in,
And all the while to render Venus more
A pleasure for the men- the which meseems
Our wives have never need of.
...