Distillery swill and brewers grains, which formed important components of "cow-food," are no longer found in these places. No serious difficulty attended the efforts of the district inspectors in securing compliance with the regulations in this respect. By referring to the tabulated statement on page below it will be seen that the percentage of adulterated milk is lower than the preceding year (1895). The following exhibits the yearly average percentages of condemned milk since the establishment of milk inspection: This is not upon the entire supply of this City-let it be understood-but only that proportion of it as found in the shops and wagons of dealers. The results of milk inspection may be appreciated when it is stated that the examinations into the character of milk supplied to consumers in 1889, when milk inspection was first started, disclosed watered and skimmed milk to the extent of 76.56 per centum of the samples examined. The quantity inspected being but a very small fraction of the supply, as a matter of course, it afforded data only upon which to base an estimate of the probable quantity sold as the pure article to consumers.* Note.-Sixty-four samples were taken promiscuously from the wagons and shops of the dealers without regard to quality or the standing of the dealer, and submitted to Dr. Cresson, at that time Chemist to the Board of ! Health, for analysis, with the result as follows: thirty-six samples or fifty-six and twenty-five one-hundredths (56.25) per cent. were watered; thirteen samples, or twenty and thirty-one one-hundredths (20.31) per cent. were partly skimmed; and the balance, fifteen samples, or twenty-three and forty-four one-hundredths (23.44) per cent. standard milk. It will be seen by the foregoing that only twenty-three per centum of the milk sold at the time these samples were taken were shown by analysis not to have been tampered with. Taking the 56.25 per centum of milk adulterated by water only, found at the time as indicating a fair average of the total annual supply, we have about fifty-seven million quarts of watered milk sold as normal milk. In dollars and cents that would mean the payment by consumers, in that year, of between three and four millions of dollars for watered milk. Testing Milk. In order that milk may be tested with some degree of accuracy to warrant its condemnation several instruments are used for the purpose. To examine the greatest quantity and in the shortest possible time are considerations of the utmost importance. Whilst the results obtained by any method other than the gravimetric analysis are at best approximations, nevertheless they are sufficiently correct to govern the inspector in his action. The test employed by the Inspectors of Milk is the specific gravity test as indicated by the lactometer (Fig. 1), and thermometer. The lactometer is an instrument of the class of hydrometers and is specially arranged for milk inspection. The stem is graduated from 0 to 130, the former representing the unit of gravity which is that of water, 1 or 1.000, and the latter, 1.03770, specific gravity. By referring to page 350 the equivalents in gravity to the arbitrary figures on the stem of the lactometer will be seen. Milk being heavier than water its specific gravity varies according to the amount of solid matter it contains. These are known as total solids, and consist of caseine, milk sugar, fat and salts or mineral matter, and in average milk should show from thirteen (13) to thirteen and one-half (13.50) per centum, and a specific gravity of 1.03190, or 110 on the lacto meter stem. An erroneous impression prevails amongst many persons who use the lactometer, that if milk shows 100 on that instrument or 1.02900 specific gravity, that it is pure and unadulterated. The falsity of this proposition is demonstrated as follows: Suppose a sample of normal milk is of 1.03190 specific gravity or 110 on the lactometer, and ten per centum of water be added which would lower the gravity to 1 02900 or 100 lactometer reading. It will be seen how milk of an average quality may be tampered with successfully if such standards of gravity were established. The experiments of numerous eminent chemists comprising innumerable tests range from a minimum of 1.02900 to a maximum of 1.0354 specific gravity, the average being 1.03220 or 111 on the lacto meter. 10 60 70 90 700 110 120 130 Fig. 1. |