4Ryan, John. The History and Antiquities of the County of Carlow. Dublin: Richard Moore Tims, 1833. 338. This account may be read in its entirety here.
Rickets is a disease, now primarily suffered by children in developing countries, caused by a lack of vitamin D, calcium, or phosphate, or other dietary needs. It leads to softening and weakening of the bones.
William Wakeman's discussion (1903) of the Aghade Holed Stone and similar specimens may be read in its entirety here.