316 STATE BOARD OF AGRICULTURE. 



"Kijrhty-cight guinea pigs were inoeuhitcd witli milk from lifteen ilillerent cows. 

 TuluTculosis was found in twelve ami these results came after the use of milk or 

 ercam from six dillerent aninuils." 



III. IiKHulation of rabbits. 



"Ninety-live rabbits were used for the same ])\irpo8cs and under the same con- 

 ditions as were the guinea j)igs. Of these rabbits, live were for various reasons 

 useless for purposes of investigation, leaving ninety which were subjected to full 

 «.\amination. For these ninety animals milk from nineteen dillerent cows was used 

 one or more times and tuberculosis was found in six animals inoculated with milk from 

 four dillerent cows." 



IV. Kabbits fed with milk. 



"There were used forty-eight animals with positive (tuberculosis) results in two, 

 and both of these animals were fed iipon milk from a single cow." 



V. Pigs fed with milk. 



"Twelve healthy animals were used with positive results (demonstration of the 

 bacilli under the microscope) in five. In two others, nodules presenting the gross 

 ap])earance of tuberculosis were found, but the material was not saved for microscopic 

 examination. In any case, nearly fifty per cent of the animals were shown to be 

 tuberculous." 



Vl. — Calves fed witli milk. 



"Of these twenty-one animals, eight, or over 33 per cent, were shown to be 

 tuberculous." 



All of these cows were free from tuberculosis of the udder. 



Hay made five hundred sixty-three tests for tubercle bacilli in milk, three hundred 

 fifty-nine unmixed and two hundred four mixed milk. In the three hundred fifty-nine 

 tests he found fifty-one containing tubercle bacilli and in the two hundred foiir mixed 

 milk tests he found four containing tubercle bacilli. Of nine tests made by Buege 

 with the market milk of Halle, two gave evidence of tuberculosis. Two animals were 

 used in each test. Both animals died which were inoculated with one sample and 

 only one of the two inoculated with another sample. Dr. Sydney Martin examined 

 the milk from ten tuberculous cows with apparently sound udders and did not find the 

 bacilli in any of the milk. With the milk from five tuberculous cows with tuberculous 

 udders inoculated into twenty-one guinea pigs, tuberculosis resulted in each instance. 

 No diminution was noted in the virulence for a dose of even 5-100 to 1-10 c. c. diluted 

 with wholesome milk. Dr. Hope of Liverpool states that the investigations of the 

 bacteriologists showed that 2 8-10 per cent of the samples of milk taken from the city 

 shippers contained the tubercle bacillus. 



Professor Allan INIacFadyean makes the following report on one liundred samples of 

 milk taken from the Hackney District, England: 



"Jenner Institute of Preventive Medicine, August 3, 1899. 



Sir — I beg to submit the following rej)ort upon the samples of milk forwarded 

 by you to the Jenner Institute for examination as to the presence of tubercle bacilli: 



The samples of milk (one hundred in number) were received at intervals from 

 March to May 30, 1809. The fresli samples Avere examined immediately on their 

 arrival. The milk was centrifugal ised for thirty minutes, the cream was then stirred 

 from the top, and the whole eentrifugalised for a further period of thirty minutes. 

 In this way the bacteria present in the milk were sedimented. The sedimentcd portions 

 of the milk were used for examination. A series of microscopical specimens was made 

 from each sample, but such a direct examination does not yield satisfactory results. 

 The only reliable test is by means of inoculation experiments and these were carried 

 out with each sample of the milk. The accompanying table gives the results obtained, 

 both positive and negative. 



A period of four to six weeks must elapse before the diagnosis can experimentally 

 be established and the investigation has consequently extended over some months. 



The result niay be briefly summarized: 



1. Seventeen samples of milk were found to contain tubercle bacilli of virulent 

 cliaracter. 



2. Twenty-three animals succumbed prematurely. It was consequently impossible 

 to establish a diagnosis in these instances. 



3. Seventy-seven samples were therefore fully and fairly tested. Taking the 77 



