THE MILK SITUATION IN THE DISTBICT OF COLUMBIA. 359 



" That tuberculin, properly used, is an accurate and reliable diagnostic 

 agent for the detection of active tuberculosis. 



" That tuberculin may not produce a reaction under the following conditions : 



"'() When the disease is in a period of incubation. 



"(&) When the progress of the disease is arrested. 



"(c) When the disease is extensively generalized. 



" The last condition is relatively rare and may usually be detected by physical 

 examination." 



Thirty-three cities in the United States now require that herds which supply 

 their milk be tuberculin tested. Error in the application of the tuberculin 

 test has never been found to be greater than 3 per cent. 



VIEWS OF DB. SCHBOEDEB. 



Dr. Schroeder testified as follows : 



The efficiency of the tuberculin test has been well demonstrated and it is 

 hardly necessary to say anything more on the subject. When we consider that 

 the tuberculin test gives an accurate diagnosis of tuberculosis in cattle, in 

 between 98 and 99 per cent of the cases, we must recognize that we have a 

 more reliable diagnostic method in this disease than in any other known dis- 

 ease. I have given the tuberculin test a great deal of attention throughout 

 many years. I have given animals as high as 1,000 doses of tuberculin at a 

 single time and in healthy animals it produces no injury. 



We use at the experiment station a great many animals in various forms 

 of experiments. Before using them we inject tuberculin to assure ourselves 

 they are perfectly well. We have injected large quantities of tuberculin into 

 well animals and they have shown no symptoms of trouble, and after being 

 killed have been found perfectly well. 



At the experiment station I had a number of animals from District herds, 

 apparently in the best of health, so far as physical examination was concerned. 

 We submitted them to the tuberculin test and 40 per cent, apparently healthy, 

 reacted. 



HUMAN AND BOVINE TUBERCULOSIS. 



Relative to human and bovine tuberculosis, from the researches of the German 

 and British investigating commissions, and independent investigators, we know 

 that bovine tubercle bacilli are fairly common in human beings. 



There was one interesting feature brought out at the last International Con- 

 gress on Tuberculosis. It was an investigation by W. H. Park, of the New York 

 research laboratory. Twenty-six per cent of the children under 5 years ex- 

 amined by him and found to have tuberculosis were affected by bovine tubercle 

 bacilli. 



I do not believe it is necessary to add anything to this. We have the efficiency 

 of the tuberculin test thoroughly demonstrated, and the frequent occurrence of 

 bovine tuberculosis among children alone shows we must eliminate those cattle 

 or do something to the milk to prevent it doing injury. That something is 

 pasteurization. 



The tuberculin test should be required of all dairy herds. Where it is not 

 required, all milk should be pasteurized before it is used. This should apply 

 not only to milk and cream used in their raw state, but to all milk and cream 

 contained in ice cream, buttermilk, butter, and cheese. 



I have demonstrated that 40 per cent of apparently healthy cows that have 

 tuberculosis in its early stages pass tubercle bacilli in the feces. Unquestion- 

 ably, much of the tubercle bacilli in milk enters it in this way. Tuberculous 

 cows whose milk does not show the presence of tubercle bacilli pass the bacilli 

 in the feces, and for this reason their product can not be safely used unless it 

 is pasteurized. This shows the menace in the apparently healthy cow that has 

 not been tuberculin tested. 



Dr. Anderson's recital of his observations concerning the milk supply of 

 Washington follows: 



Just prior to October, 1907, 1,147 cows of the District of Columbia were 

 given the tuberculin test, and 214, or 18.6 per cent, responded. About the same 

 time 1,059 cows from 51 herds of Virginia, Maryland, and the District, supply- 

 ing milk to Washington, were tested; of this number, 160, or 15.1 per cent, 

 reacted. These figures do not give a fair idea of the prevalence of tuberculosis 

 in the herds supplying milk to Washington, as only the owners of those herds 



