'Gunning quite literally takes the traditional "Pills Of White Mercury" by the scruff of the neck and delivers a spirited rendition that makes the song his own. Geographically speaking, it's set in my native North East Scotland. The opening verse mentions the River Ugie, which sheds its waters into the North Sea on the northern outskirts of the fishing port, Peterhead. At the outset, the narrator " ...spied a dear comrade, dressed in white flannel " who had died of syphilis, a disease from which, because of his own loose social habits - and despite his parents' repeated warnings, the narrator is also suffering. When Gunning introduced this song during his Kerrville 2004 mainstage set, he commented that he had first heard it performed by a Scottish band. By way of settling his affairs, in the closing verse the narrator requests " Now get you six strong fellows to carry my coffin, Six pretty maids to bear up my pall, And give each of them a bunch of red roses, So when they pass by me they'll not know the smell ."'

from       www.davegunning.com/news.html



Also google

Pills of White Mercury

And if you google

"Pills of white mercury", history

There is stuff there that will lead you to the 'cat.