412 STATE BOARD OF AGRICULTURE 



microbe must be present ere this disease in its inception can come into 

 existence. In 1882, Dr. Robert Koch, of Berlin, claimed the discovery 

 and demonstrated the true and essential cause of tuberculosis — the tu- 

 bercle bacillus. He also showed the bacillus present in all tubercular 

 lesions. He isolated and cultivated the germs from tubercular tissue, 

 and produced tuberculosis artificially in animals by inoculation with 

 pure culture. At this time the doctor was looking for a cure for con- 

 sumption in the human family. 



He failed in this effort, but a few years later produced and experi- 

 mented with a "lymph" or ''tuberculin," which has since become a valu- 

 able diagnostic agent in demonstrating the presence of tuberculosis in 

 animals, even in the early stages of the disease. 



Regarding the list of micro-organisms, it is stated as an undeniable fact 

 that the bacillus tuberculosis, although the most infinitesimal of them all 

 (about one ten-thousandth of an inch in length), is at once a despot and a 

 millionaire. It will live in ice, maintain vitality at a temperature below 

 150 degrees F., resists moisture, drouth and decay, and bids defiance to 

 the germicidal action of the gastric juice. It is the czar of all mankind, 

 and is responsible for more deaths among the human race than any other 

 germ, while more people die annually from consumption than from war, 

 pestilence and famine. 



HOW TUBERCULIN IS MADE. 



It is made from a pure culture of the tubercle bacillus, highly concen- 

 trated, then filtered through porcelain, after being sterilized by heating 

 to a high temperature to destroy any and all germs. It is in liquid form, 

 diluted with glycerine and carbolic acid, and is furnished to our commis- 

 sion by the Bureau of Animal Industry of the Department of Agriculture 

 at Washington. 



THE TEST. 



In testing cattle for tuberculosis we take and record the average nor- 

 mal temperature of each animal during the first day. Several tempera- 

 tures are taken, preferably two hours apart. The average normal tem- 

 perature of cattle is about 101 degrees. 



In the evening of the first day we inject two cubic centimeters under 

 the skin of each full grown animal by means of a sterilized syringe. A 

 smaller amount is injected into the system of younger animals, varying 

 according to age and size. Commencing early the following morning, 

 we take hourly temperatures of each injected animal during the day. 

 Tuberculous cattle respond by a rise in temperature of two degrees or 

 more from the twelfth to the twentieth hour after injection. A rise of 

 two degrees over the normal temperature after injection indicates the 

 presence of tuberculosis, unless there is some physical disturbance, such 

 as the cows being in heat, near or recently past parturition; but if the 

 animal is healthy, there should be no rise in temperature, and no possible 

 injury to the cow. 



During these tests the temperature is taken with tested or accurate 

 thermometers. Much pains must be taken, and only experts should be 

 allowed to make the tuberculin test. The hundreds of thousands of 

 animals tested in this country, under the direction of competent veterin- 



