The Boii, as we know them, belonged almost certainly to the Early Iron age. They probably used long iron swords for dealing cutting blows, and from the size of the handles they must have been a race of large men (cf. Polybius ii. 30). For their ethnological affinities and especially their possible connexion with the Homeric Achaeans see W. Ridgeway's _Early Age of Greece_ (vol. i., 1901). See L. Contzen, _Die Wanderungen der Kelten_ (Leipzig, 1861); A. Desjardins, _Geographie historique de la Gaule romaine_, ii. (1876-1893); T.R. Holmes, _Caesar's Conquest of Gaul_ (1899), pp. 426-428; T. Mommsen, _Hist. of Rome_, ii. (Eng. trans. 5 vols., 1894), p. 373 note; M. Ihm in Pauly-Wissowa's _Realencyclopadie_, iii. pt. 1 (1897); A. Holder, _Alt-celtischer Sprachschatz_. BOIL, in medicine, a progressive local inflammation of the skin, taking the form of a hard suppurating tumour, with a core of dead tissue, resulting from infection by a microbe, _Staphylococcus pyogenes_, and commonly occurring in young persons whose blood is disordered, or as a complication in certain diseases. Treatment proceeds on the lines of bringing the mischief out, assisting the evacuation of the boil by the lancet, and clearing the system. In the English Bible, and also in popular medical terminology, "boil" is used of various forms of ulcerous affection. The boils which were one of the plagues in Egypt were apparently the bubonic plague. The terms Aleppo boil (or button), Delhi boil, Oriental boil, Biskra button, &c., have been given to a tropical epidemic, characterized by ulcers on the face, due to a diplococcus parasite.