In tests of 40 samples of milk from the supply of the city of Edinburgh:
(1) The bacterial content was, on the average, high but not abnormally so when compared with that of the milk supply of other cities. It ranged from 20,000 to 29,000,000 per c.c.
(2) The results of the reductase test corresponded well with the bacterial counts and the test is recommended for obtaining a good rough idea of the bacterial numbers present, where results are required in a short time.
(3) About half of the samples contained lactose-fermenting organisms in unduly high numbers; this is attributed chiefly to the lack of attention to cleanliness in production.
(4) The value of the fermentation test for speedily indicating the nature of bacterial contamination is pointed out. In a general way the test corroborated the results of counts of the lactose fermenters and indicated that a number of the samples, which did not produce blown curds, contained large numbers of undesirable organisms.
(5) Taken as a whole, the results seem to indicate not so much particularly high contamination as contamination of a very undesirable nature. They point to the necessity of educating the producer and distributor in the principles underlying the production of clean milk and emphasise the importance of proper control of the industry from this point of view.