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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    blood. In addition to these two organisms the local lesions several times contained the staphylococcus pyogenes aureus. 9. To sum up the points brought out by the examination of the series of forty-five mixed milks, the following statements may be made. (i.) They were all more or less contaminated with extraneous matter, animal and vegetable, evidently derived from the cow, the stable, milk pails, cans, etc. (2.) Cells from the udder were present in all cases, but sometimes they were very few in number, at other times they were excessively abundant. The milks which proved by inoculation to be tuberculous contained in all cases a large number of cells, but other milks containing many cells produced no tuberculosis, and sometimes even not more inflammation than milks containing very few cells.^ (3.) Twenty-nine out of the forty-five specimens contained a large number of bacteria of various kinds.^ 1 The cells present were chiefly large and small eirithelial cells, vacuolated or not; debris of these cells were very frequent, and often resembled leucocytes. Leucocytes were present in a little more than half the cases, but were very seldom numerous. A few large epidermal scales were seen in about half the cases. - As the organisms present were not isolated and cultivated it is difficult to speak positively regarding their identity, but I made careful microscopical examination in all cases, and the followng tyjies of microbes were found. (1) Staphylococci almost always. (2) Streptococci in less than half the cases. (3) Diplococci in about half the cases. (4) Tetrades or sarcinre iu about one-fifth of tlie cases. (5) A bacillus having all the morphological features of the bacillus lacticus was invariably present and sometimes excessively abundant; in five or six cases, however, it was very scanty. (6) Another short bacillus resembling the bacillus coli was present in many cases. (7) Long slender bacilli were not very frequent. (8) Thick long bacilli resembling the bacillus subtilis were found in nearly half the cases, but were seldom numerous. (9) Yeasts and Oidia were also found in a number of cases, but they were seldom abundant. I have in the first part of this paper omitted accidentally to mention the method which I used in preparing specimens of milk for microsco]iical examination. After the milk has been centrifugalised, the sediment is separated by removal of tlie supernatant fluid; this is done by aspirating the fluid by means of an air pump so as not to disturb the sediment. This may seem an unnecessary complication, but anybody who has tried to obtain a sediment free from cream after milk has been centrifugalised must have found that it is not at all easy to aspirate or syphon off the layer of cream, which is very dense and STCPILISCD TUBE WITH AWIOt OPENING AT LEAST ''a INCH IN OlAM resistant. Having exposed the sediment, a sample is taken with tlio sterihsod plntmum loop and snread over a cover-glass. The film is allowed to dry, and immediately after fixed in the flame of a Bm sen burner in the usual way. The cover-glass is tlien placed in a small •'oY^ed capsule into w X^s poured about i to i ounce of absolute ether and absolu e alcohol (equal parts , in tins it . if fo/ rom wo hours (at least) to twenty-four hours, after which he covero.l '^n!'>'l<;>s pl«ce'i n fshallow lisii full of very hot water, so as to bring the ether to the boiling point or 1 cai it Afier one-qunrter lo haH the cover-glasses are taken out, well washed with absolute