The analysis of food and drugs / by T.H. Pearmain and C.G. Moor.

  • Pearmain, T. H. (Thomas Hames)
Date:
1897-1899
Catalogue details

Licence: Public Domain Mark

Credit: The analysis of food and drugs / by T.H. Pearmain and C.G. Moor. Source: Wellcome Collection.

    81/332 (page 63)
    to the presence of the infection in the persons immediately concerned in drawing or handhng the milk, or to the absence of cleanliness either in the water or in the other surroundings. The meaning of cleanliness in the water in the present sense is freedom from bacterial contamination; and it is unquestionable that unless an exceptionally pure source of supply is at hand, no water should be allowed to be used for dairy purposes unless it has been boiled, or, preferably, passed through a Pasteur filter immediately before use. It must be borne in mind that some organisms, such as typhoid, find in milk a medium capable of favour- ing their multiplication at an enormous rate, and the film of damp which is inevitably left on a vessel after cleaning may serve to contaminate the whole of the milk which may be poured into it if it be kept for a few hours. The standard of purity of water for dairy purposes is not to be estimated chemically, nor in the presence of a medium in which the number of bacteria in the water is liable to in- crease at so enormous a rate is the criterion of a small number of bacteria any substantial protection. The sole criterion which can be admitted, and the only one which, in the absence of direct chemical contamination such as that which may arise from lead pipes, is necessary, is that the water be absolutely sterilized before use. In the same way the presence of dust must be avoided where milk is about. There is no practicable method of purifying dust, and not only tuberculosis, but probably the peptonizing organisms described above, both of which are liable to assume forms of the highest resistance and permanence, are largely conveyed by way of dust. Finally, it must be remarked that under the influence of various organisms, which are only now beginning to be identified, milk undergoes decompositions resulting in the production of direct poisons—such, for instance, as the