propolis is more or less the glue of the hive. They will use it to close up holes and seal cracks as iddee said. As for its medicine value it is an anti bacterial that is usually made into a tincture or a topical ointment to aide in the healing of cuts and abrasions. which helps keep the infection away. If you search back in history you will find propolis remedies have been around longer than modern medicine.
"gathered from alder, poplar and horsechestnut, and various exudations from wounds in any woody plant."
"It is made up of an indeterminate number of substances, and thus has no specific chemical formula."
"...used as a putty, especially when mixed w/ wax."
"... special varnish used by Stradivarius, the violin maker."
I know it is used in cosmetics and toothpaste. Tom's brand comes to mind.
A friend of mine has collected it from scrapping supers during the extracting process. I don't know if he will be doing that this year or not, because, last I heard, Beehive Botanicals is shut down.
How up to date does one need to be? Mine is a 1985 first print edition and weighs about the same as a 1 KVALITETE jar of Lavanda honey from Coatia. Sittin' right there on my book shelf. You know what books are, don't you? Much more satisfying than on line info sources.
My Dad sometimes said, "Pity the poor man who can't spell a word more than one way." Trouble is, he could misspell the word right 5 different ways in one letter. I think he was proud of his ability or, like me, was lazy.
Anyway, I liked what you said and how you said it.