Quiz question

[Tillys Mum]

Can anyone help with this one:

A Roman mixture of honey, salt and vinegar was the first example of this?

Thanks

[ronianna]

I'm 99% sure it was used as a contraceptive method - how etc I'm not quite sure! Would be nice if someone could back me up on this?

[silly moo]

It was an energy drink used by roman soldiers whilst marching.

http://www.florilegium.org/files/FOOD/Vinegar-art.html

[rojash]

There seem to be thousands of references to these ingredients in Roman medicine, but usually combined with some vegetable or herb to achieve a specific effect. I can't find any reference to their use in contraception!

[rojash]

silly moo, I was also going to mention an energy drink, but I can't find any reference to salt in the document you refer to, although it would certainly make sense.

[Marsh]

According to this  the first known contraceptive was crocodile dung, used by the ancient Egyptians. 
Google keeps sending me to pages of Roman recipes.  Could the mixture have been the first marinade?