State control of tuberculosis.

  • Charles V. Chapin
Date:
1900
Catalogue details

Licence: Public Domain Mark

Credit: State control of tuberculosis. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    for all animals imported into the State, it is said that 10 per cent, of the animals tested ])rove to he tuher- ciilons. There is ahnost no tnherculosis among the eattle on the ranges in the West, and the most is found among the dairy herds which sn])ply the Eastern cities. Veterinarians seem to he very generally agreed that tuberculosis among cattle has increased considei'ahly during the last few years, at least until steps began to be taken for its eradication. It has been suggested that the tuberculosis of man and of the other animals may not be identical. The bacilli which are found in the lesions of the different species are not always exactly the same. There are slight morphological and cultural differences between the bacilli usually found in man and cattle. The bovine bacilli are usually slightly shorter and straighter, and their growth upon artificial media is less luxuriant, and these characters are quite consistent through several generations of artificial cultures. There are some differences, also, in regard to the degree of viru- lence of the different forms. Theobold Smith, who has given special attention to this subject, has rarely found the bovine type in human subjects. He is, however, far from holding that the different types may not pass from one species to another. Recent bacteriological work seems to show that the morpho- logical and physical characters of most species of bacteria can be considerably changed, usually slowly, sometimes raj^idly, by change of environment. Thus, although ordinarily the tubercle bacillus does not grow at a temperature below 98*^ F., it can be made to do so by careful manipulation, hy gradually reducing the temperature for successive generations. The general