udder, flank, and legs of the animal were thoroughly cleansed with water; a second gelatine surface was then exposed in the same place and for the same length of time. The results of these two experiments are very instructive. When the cow was milked without any special precautions being taken, 3,250 bacteria were deposited per minute on an area equal to the surface of a teninch milk-pail; after, however, the animal had been cleansed, only 115 bacteria were deposited per minute on the same area.

Thus a large number of organisms can, by very simple precautions and very little extra trouble, be effectually prevented from obtaining access to milk. Even in the event of the milk being subsequently Pasteurised, clean milking is of very great importance; but still more imperative is it when it is destined for consumption in its raw, uncooked condition. If we consider how cows become covered with dirt and slime, that obstinately adhere to them when they wade through stagnant ponds and mud, and realise the chance thus afforded for malevolent microbes to exchange their unsavoury surroundings for so satisfactory and nourishing a material as milk, then indeed precautions of cleanliness, however troublesome, will not appear superfluous.

That a very real relationship does exist between

the bacterial and dirt contents of milk has been clearly shown by actual investigation. A German scientist has made a special study of the subject, and has determined in a large number of milk samples the amount of foreign impurities present per litre, and the accompanying bacterial population per cubic centimetre.

The following results may be taken as typical of those obtained: in milk containing 36.8 milligrammes of dirt per quart as many as 12,897,600 bacteria were present per cubic centimetre; in cleaner samples, with 20'7 milligrammes of dirt per quart, the number of bacteria fell to 7,079,820; whilst in a still more satisfactory sample, containing 5.2 milligrammes of dirt per quart, there were 3,338,775 bacteria per cubic centimetre.

Such results indicate how important a factor is scrupulous cleanliness in milking operations in determining the initial purity of milk, for there is no doubt that bacterial impurities in milk are in the first instance, to a very great extent, controlled by the solid impurities present.

I do not know of any determinations which have been made of the actual amount of such solid impurities present in our public milk-supplies, but such estimations have been made in many of those belonging to large cities in Germany. Thus, Professor Renk found in a litre of milk supplied to

Halle about 75 milligrammes, whilst in another sample as much as o'362 grammes per litre were detected. In Berlin 10 milligrammes, and in Munich 9 milligrammes per litre, were found. Dr. Backhaus has estimated that the city of Berlin alone consumes daily with its milk no less than 300 cwt. of cow-dung. If we associate these amounts of solid impurities with their consequent bacterial impurities, then we shall obtain some idea of what the microbial population of these milksupplies may amount to.

These impurities are almost wholly preventable, but, unfortunately, but little importance is apparently attached to their presence in milk as a rule by dairymen.

In a letter published in the Sussex Daily News a correspondent and well-known authority on dairy matters sounds a timely note of warning to our dairy managers :—

"I happen to know," he writes, "for a fact that Americans who visited one of our Dairy Shows at Islington were so disgusted at the method or rather lack of cleanly method-exhibited there as our ordinary way of milking cows, that these visitors stated that nothing would induce them to drink milk while in England. I mention this circumstance so as to bring home to the minds of English dairy-farmers who may read this letter how very backward we are in this country as compared

with more studious and careful foreign competitors. It is insisted upon by our foreign teachers that our cow-stalls are too short and not roomy enough, and our cow-houses badly constructed; that we do not (1) groom our cows or (2) clean the teats, nor (3) sponge their udders, bellies, and sides before milking with clean, tepid water; (4) that the milkers do not tie up the cow's tail nor clean their own hands and persons, nor (5) cover their clothes with a clean, well-aired blouse during milking; that (6) they generally milk in a foul atmosphere (bacterially), tainted with the odour of dung, brewer's grains, or farmyard refuse. I am sorry to state that there is too much solid fact about the contentions which, based upon bacteriology, are given as causes of injury to quality. . . . Cleanliness is now a matter requiring the primary attention of English dairy-farmers. The study of bacteria proves that such inattention is greatly the cause of foreign butters beating ours."

It follows as a natural sequence that all the cans and vessels used for dairy purposes should be absolutely beyond suspicion of contamination. Professor Russell has shown by actual experiment that, even where the vessels are in good condition and fairly well cleaned, the milk has a very different bacterial population when collected in them and in vessels sterilised by steam.

Two covered cans were taken, one of which had been cleaned in the ordinary way, and the other sterilised by steam for half an hour. Previous to milking the animal was carefully cleaned, and

special precautions were taken to avoid raising dust, whilst the first milk, always rife with bacteria, was rejected. Directly after milking bacterial gelatine-plates were respectively prepared from the milk in these two pails, with the following results In one cubic centimetre of milk taken from the sterilised pail there were 165 bacteria; in that taken from the ordinary pail as many as 4,265 were found.

Another experiment illustrates perhaps even more strikingly the effect of cleanly operations in milking upon the initial bacterial contents of milk. The preliminary precautionary measures were carried out by an ordinary workman, and are in no sense so refined as to be beyond the reach of ordinary daily practice. "The milk was received in steamed pails, the udder of the animal, before milking, was thoroughly carded, and then moistened with water, so as to prevent dislodgment of dirt. Care was taken that the barn air was free from dust, and in milking the first few streams of milk were rejected. The milk from a cow treated in this way contained 330 bacteria per cubic centimetre, while that of the mixed herd, taken under the usual conditions, contained 15,500 in the same volume. The experiment was repeated under winter conditions, at which time the mixed