[83] Ravenel, Journ. of Comp. Med. & Vet. Arch., Dec. 1897; Hartzell, Journ. Amer. Med. Ass'n, April 16, 1898.
[84] Stille, Brit. Med. Journ., Aug. 19, 1899.
[85] This test is made by injecting into the animal a small quantity of tuberculin, which is a sterilized glycerin extract of cultures of the tubercle bacillus. In a tuberculous animal, even in the very earliest phases of the disease, tuberculin causes a temporary fever that lasts for a few hours. By taking the temperature a number of times before and after injection it is possible to readily recognize any febrile condition. A positive diagnosis is made where the temperature after inoculation is at least 2.0° F. above the average normal, and where the reaction fever is continued for a period of some hours.
[86] Martin, Brit. Med. Journ. 1895, 1:937; Nocard, Les Tuberculoses animales, 1895.
[87] C. O. Jensen, Milch Kunde und Milch hygiene, p. 69.
[88] Ostertag, Milch Zeit., 22:672.
[89] Obermüller, Hyg. Rund., 1897, p. 712; Petri, Arb. a. d. Kais. Ges. Amte, 1898, 14: 1; Hormann und Morgenroth, Hyg. Rund., 1898, p. 217.
[90] Rabinowitsch, Zeit. f. Hyg., 1897, 26: 90.
[91] Th. Smith. Journ. of Expt. Med., 1899, 4:217.
[92] Russell and Hastings, 18 Rept. Wis. Expt. Stat., 1901.