London's Pulse: Medical Officer of Health reports 1848-1972
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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
Malden and Coombe 1962
[Report of the Medical Officer of Health for Malden & Coombe]
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(28)
details of milk testing
| class OF milk | number of samples tested | appropriate tests | number op samples | ||
|---|---|---|---|---|---|
| passed | FAILED | void | |||
| Pasteurised | 39 | Phosphatase | 39 | - | - |
| Methylene blue | 36 | - | 3 | ||
| Sterilised | 2 | Turbidity | 2 | - | - |
| Tuberculin tested (Pasteurised) | 22 | Phosphatase | 22 | - | - |
| Methylene blue | 19 | - | 3 | ||
| Tuberculin tested (Raw) | 3 | Methylene blue | 2 | 1 | - |
| Tuberculin tested (Farm Bottled) | 2 | Biological | 2 | - | - |
The purpose of the phosphatase and methylene blue tests is to
determine respectively whether or not the milk has been adequately heat
treated and whether it is of good keeping quality.
The turbidity test for sterilised milk is to determine whether
or not the milk has been adequately sterilised.
The greater importance must be attached to the phosphatase test
as correct heat treatment or pasteurisation reasonably ensures that all
pathogenic organisms have been eliminated.
Void samples are those received at the laboratory at a time when
atmospheric shade temperature exceeds 65°f.
The sample which failed to pass the Methylene blue test was
purchased from a vending machine and subsequent samples proved to be
satisfactory.