I kid you not, it was real saliva collected from elderly patients that had dysphagia! The research project was trying to see if there was some properties of saliva that led to the symptoms of the disease and trouble swelling liquids.
It always grossed me out. It was just this big plastic bin with jars filled with saliva. It did have some bright yellow caution stickers that told everyone else not to play with the saliva. For some reason this is vividly burned in my mind :)