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93
Preservation of samples taken.
Attention was called to the desirability of providing a refrigerator for preserving,
especially during the week-end, samples of food and drugs taken by the Council's officers for
analysis. This has now been provided and is particularly useful during the hot weather,
WORK OF THE PUBLIC ANALYST.
The following Notes have been supplied by the Council's Analyst,
Mr. J. Kear Colwell, f.i.c.
During the year 1934, 815 samples were submitted for analysis in accordance with
the provisions of the Food and Drugs (Adulteration) Act, 1928, 344 having been purchased
with the required formalities and 471 obtained informally.
Of this total 38 (or 4,66 per cent.) proved to be adulterated, 16 being samples submitted
formally and 22 informally. The adulterated articles consisted of Apricots, Butter, Milk,
Pepper, Sausage Roll, Sausages, Sausages (Veal), Sweets, Tomato Puree, and Vinegar (Malt).
Milk.—402 samples of Milk were analysed and 24 of these (5 97 per cent.) fell below
the limits required by the Hoard of Agriculture Regulations—3.0 per cent, for fat and
8.50 per cent, for non-fatty solids—and were certified to be adulterated accordingly.
From 11 of these 24 samples, fat had been abstracted, the amount of the deficiency
varying from at least 3.0 per cent. to at least 31.0 per cent.; and to 13 others additions of
water had been made, the quantity added varying from at least 3.5 to 14.1 per cent.
In this connection it may be interesting to note that practically certain evidence is now
obtainable for the determination of the addition of water to milk, by means of the freezing
point. Milk as given by the cow has a freezing point, which is almost constant, of 0.55°C.,
and if the sample freezes at a higher point it affords undoubted indication that water has been
added to the milk after "it comes from the cow." In practice a limit of 0.530°C. has
been generally adopted as a standard for calculation of the amount of extraneous water. So
far, this valuable test as to the genuineness or otherwise of milk is only applicable to fresh
milk or milk which has not been allowed to become too acid, as it naturally does on keeping,
but the experience of a large number of analysts with many thousands of samples clearly
shows that the results obtained from it are practically infallible.
It may be interesting to add a table prepared by the Public Health Department from
the returns of the Borough Analyst showing the composition of the genuine samples of milk,
month by month, during the j'ear 1934.