Too good to pass up.
The claim of 'blood signing was not an "urban myth" – if it was a false claim, as is 90% probable, it was one started by Unionists, circulated by Unionists and still maintained by some Unionists – a sign of their fanaticism, which was the point I was making in drawing attention to it.
Jim Carroll

"and the other incident was that, among some twenty men who signed the Covenant in Belfast with their own blood, Major Crawford was able to claim that he was following a family tradition, inasmuch as a lineal ancestor had in the same grim fashion emphasised his adherence to the Solemn League and Covenant in 1638."
The Claim

The Covenant had two basic parts: The Covenant itself, which was signed by men, and the Declaration, which was signed by women. In total, the Covenant was signed by 237,368 men; the Declaration, by 234,046 women. The most passionate signatories signed in their own blood.
And again

A forensic test determined to recognise the iron content of blood has now returned a 90% confidence that the signature was not in fact made in blood - though some Unionists are still holding onto the 10% uncertainty factor!
hThe ongoing claim by Unionists
Jim Carroll