Nevertheless, I suspect that cigarettes were already described as “coffin nails”, long before the 1964 Surgeon-General’s Report made it official. I wonder if anyone has any early cites for “coffin nails”?
Coffin nail has been used as slang for a cigar or cigarette since at least 1888. From the OED:
1888 Texas Siftings 18 Feb. 8/1 A youth [...] puffed at an ill-smelling coffin nail.
And HDAS has this from Galaxy, 15 March 1867:
Pamela...tries to persuade me, that every puff of smoke...is a nail in my coffin.
Coffin nail is even older as slang for a drink of liquor. From Green’s:
1839 (con. 1703) W.H. Ainsworth Jack Sheppard (1917) 8: The worst nail you can employ is a coffin nail. Gin Lane’s the nearest road to the churchyard.