On second thoughts it might not be that simple because the blood has dried, but worth a go. It definitely works for fresh blood, but must be the saliva of the same person as the blood.
Jean Nathan in Poole, Dorset, UK - To unsubscribe send email to [email protected] containing the line: unsubscribe lace [email protected]. For help, write to [email protected]. Photo site: http://www.flickr.com/photos/lacemaker/sets/
