Pasteur founded the system of treating rabies by the injection of an emulsion of the spinal cord, believed to contain the poison, no bacilli being yet found. The rabies poison having a special affinity for the spinal cord, rabbits are inoculated with poison obtained from sections of the spinal cord at different stages of treatment. In the end an immunity is set up in the animals; an anti-rabic virus is obtained and injected into persons bitten by mad dogs. Pasteur Institutes, where treatment is provided for those bitten by animals, are located at convenient points throughout the United States. The treatment costs about one hundred dollars.

Tetanus Antitoxin has not proved satisfactory as a curative agent, but has been of some benefit, and is very effective as a prophylactic. Its method of preparation is analogous to that of diphtheria antitoxin, and it is similar to this in nature and action. The U. S. P. recognizes the tetanus antitoxin, Serum An-titetanicum, and also the refined concentrated serum and the dry form. The average dose is: hypodermic, 10.000 units, protective, 1500 units. The dry antitoxin is designated as a hundred-fold normal antitoxin - i.e., 1 Gm. is sufficient to neutralize 100 Gm. of the normal poison of tetanus. It is put up in 5 Gm. vials, this quantity being theoretically sufficient to effect a cure. The vialful is dissolved in 30 mils of sterilized water at 40° C., and injected hypodermically at a single dose. The liquid form is of fivefold normal strength, and is employed hypodermically in cases of wounds where there is reason to fear development of tetanus, in quantity proportionate to the condition of the patient and the length of time elapsed since the injury. The antitoxin should not be kept long because it spoils readily. It should be injected in the same way as diphtheria antitoxin. Large doses used thoroughly will influence many cases of tetanus favorably if anything will.

Antityphoid Serum is prepared in much the same way that the antitoxins are prepared, but the immunizing period in the horse is much longer, being about one year. In cases of typhoid fever the Chante-messe serum is injected into the flexor surface of the elbow, about the plexus of large veins, in doses of 8-10 mils, and in a week, if the fever persists, 4-10 mils are again injected. A prophylactic dose of 2 mils may be used for those exposed to the disease.

Antiplague Serum made by Yersin has proved of value in treating the bubonic plague. It is given in doses of 150-300 mils.

Tubercular Serum (Behring, Koch, Fisch, or Mara-gliano) is used in the treatment of early cases of tuberculosis where there is no mixed infection, in a gradually increasing dose of 0.2-2 mils over a period of two years. Tuberculin (Koch), prepared by extraction of pure cultures of tubercle bacilli with 40-50 % glycerin and repeated precipitation with alcohol, as a snow-white mass soluble and stable in 50 % glycerin, is used in the diagnosis of local and pulmonary tuberculosis. The characteristic reaction to an injection of tuberculin shows itself locally by increased heat and systemically by a rise in temperature, usually in 12 hours. It is injected between the shoulder-blades at night in doses of 1/250-1/65 gr., 1/4-1 mil.