Led Zeppelin IV #8 When The Levee Breaks (backward lyrics in red)

This appears to be full disclosure by the band regarding acid use.

0:25 "Oh I, I took acid, I took acid, Oh do it, Ah In my doom I disclose it"

2:27 "Only available acid here, I said no"

5:46 "Help me or save me radium, lost at height"

I think they felt radium should have been viewed differently than the general propaganda that lead politicians to believe in it, dating back to the 1930's and the laws that were created surrounding it's use. Herbal remedy's were banned as quackery in the UK and the government shutdown anything that didn't agree with their narrative. To me it appears they were very much nature boys in so many ways.

The Cancer Act 1939 (2 & 3 Geo. 6. c. 13) is an Act of Parliament of the United Kingdom passed in 1939 to:
- make further provision for the treatment of cancer;
- to authorise the Minister of Health to lend money to the National Radium Trust;
- to prohibit certain advertisements relating to cancer;
- and for purposes connected with the matters aforesaid.

https://en.wikipedia.org/wiki/Cancer_Act_1939