Preparation , Solution of seven grains in 100 drops of water for the θ (Duffield's provings). Authorities. 1 , Henry Duffield's provings, Inaug. Thesis at Phil. Hom. Med. Coll., 1852, proving with the 5th dil. (first, second, and third days), three doses daily; 2 , Ibid., proving with 6th dil., three doses daily for four days; 3 , Ibid., proving with 30th dil., two doses daily for four days; 4 , Ibid. (a second prover), proving with 7th dil., two doses daily for four days; 5 , Ibid., proving with 30th dil., two or three doses daily for four or five days; 6 , Dr. G. Oehme, provings on self with low dilutions (symptoms appeared only after long continued and repeated dosing), N. Y. J. of Hom., 1, 367.