The examination of cow's milk for the detection of pathogenic properties / by Sheridan Delépine.

  • Delépine, Sheridan, 1855-1921.
Date:
[between 1890 and 1899]
Catalogue details

Licence: Public Domain Mark

Credit: The examination of cow's milk for the detection of pathogenic properties / by Sheridan Delépine. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    to the milk after it has left the udder to account for the marked diflerence in the properties of mixed and unmixed milks. Comparing the fate of samples which had been collected straight from the udder and of those which had been collected at railway stations, or in town dairies, it is at once evident that, after leaving the udder, the former had come in contact with nothing but sterilised bottles ; in addition to this, it was ascertained in each case that the teats of the cow and the hands of the milker were clean. In the case of the mixed milks nothing is known of the chances of contamination due to dirty udders, hands, pails, cans, etc. From the cans they were taken with due precaution to avoid any further con- tamination, but nothing more could be done. These specimens of mixed milks were, when collected, exactly in the state in which they would have reached households, but they had not suffered from any of the additional contaminations which might have occurred at the hands of the retailer, or in the households of the consumers. Many of the samples were kept in the sterilised bottles for many hours ; but this occurred equally in the case of the mixed and of the unmixed milks, so that any differences which were detected in the laboratory were clue less to the changes taking place after the taking of the samples than to what was already present in the milk when the samples were taken. 7. It is well known that milk obtained at the farm, in the usual way, is always more or less contaminated with microbes, and that these multiply very rapidly at the ordinary temperature all the year round, much more rapidly, of course, during warm than during cold weather. We have numerous observations recorded giving the number of microbes which may be found in ordinary dairy milk collected in the usual way. Gosta Grotenfelt^ gives several figures which will prove interesting in connection with the points. Samples taken in a pasture on a fresh somewhat damp summer morning:— No. of Bacteria in i cc. Imviediately after Milking. Half-hour after. Two Hours after. 10 88 1530 Samples taken in a farm at the end of the winter and under favour- able conditions:— No. of Bacteria in. i cc. 1 minediately after Milking. HalJ-hour after. Two Hours after. 106 980 3655 \VnlT^«?L°-j?^^'V Dairy Practice from a Bacteriological Point of View. Translation by F. W, vVoU, 1894. New York, p. 83 and following.