Gerard Depardieu gave Robert De Niro a homeopathic boner cure

One of France's most popular and enduring actors finally told a rapt Montreal audience the story of his threesome scene with Robert De Niro and an actress playing a harlot in the film 1900. De Niro, who has a full frontal moment or two in that sequence, asked Depardieu for help in keeping an erection during what would become one of the most famous sex scenes of the 1970s.

All he would say about it was this: 

The Cyrano de Bergerac actor shared a secret solution involving traditional Chinese heat rub Tiger Balm - allowing the then 33-year-old De Niro to perform without any further issues. [Starpulse, via PageSix]

I haven't watched the movie in years (I twice tried to make it through the plodding epic, but never made it further than early on in the second disc.) As I recall, De Niro's dong appears only once and, if that's the case, this photo shows him, uh, rather limp.

Can anyone else help with this? (The movie, not with an erection, thanks.)