I was recently shown papers relating to a West Cork family whose people emigrated to Canada in the 1810s and 1820s and the Canadian papers referred to the old family homestead. It was among the first stone houses built in the area possibly around the early 18th century. The stones were bound with a mortar made with horse hair and animal blood according to the Canadian account done in the 19th century.
On further investigation it transpired that it was was called purlow and was also used in Castle building. The McCarthy Castles in the Durrus area used it together with gravel made of rounded pebbles which seems to come from the seashore and have been graded. The material has certainly stood the test of time.
Re animal hair Sir William Willes, Chief Justice of Ireland writing of Cork 1775 remarked on the uses of produce from the abattoirs. He says extensive quantities of animal hair was produced and used in the building trade. His notes were discovered by Dr. Richard Caulfield in a London archive adn reproduced in the Cork Journal of History and Archaeology 1905.