Diphtheria Diagnosis Outfit The white cardboard box features a label with black in writings "Crookes' Diphteria Diagnosis Outfit for the rapid diagnosis of active Diphtheria. Sterilised-ready for use Directions enclosed. The Crookes Laboratories (British Colloids Ltd.) Park Royal, London, N.W. 10." and a push fit drawer containing a ball of cotton and a glass tube with a metal tip. The glass tube is empty, but it usually came with a cotton-wool on metal rod to use on the oral cavity to take a sample from the back of the throat or from a sore. 1925-1975