"The change which takes place in a sample of milk kept from contact with air, as in a bottle nearly full of the sample, and fitted with a good sound cork sealed with wax, is, as a rule, comparatively slight. The causes and nature of this change have been carefully studied by many observers, and they have been found to be perfectly definite in character. Without going into details concerning the fermentative changes to which milk is liable, it may be stated that the changes which affect the analysis, and, therefore, the inference to be drawn from the results, are concerned with the nonfatty solids only, and more particularly with the milk-sugar. The milk-sugar gives rise, either proximately or remotely, to a variety of products, the most important of which are lactic acid, ethyl alcohol, and acetic acid; but it can be shown that the only quantitative determinations which need to be made in order to determine the loss in the nonfatty matter by keeping are the proportion of alcohol, reckoned as proof-spirit, and the amount of free volatile acid, together with the ammonia derived from the alteration of the casein, or proteid substance, in the milk. The slight alterations in weight consequent on the hydrolysis and conversion of lactose into lactic acid, and the formation of certain so-called by-products of alcoholic fermentation, are partly positive and partly negative in direction, but their joint effect is too small to have any appreciable influence on the result. "The entire correction, which, of course, is always additive, in the case of a properly preserved sample from three to six weeks old is fairly constant, and may be said to range from 0.2 to 0.3 percent. In a few cases it has been found to be as low as 0.1 percent, and in very exceptional cases, as in badly secured samples, or in bottles only partially filled, it has risen to 0.7 or 0.8 percent.' "If the fermentation has passed into the butyric acid stage, the amount of free acid is greatly increased, and owing to the separated casein it is sometimes impossible to get the sample into a proper and uniform condition of analysis. In such cases the government laboratory declines to proceed with the examination. Such a result, however, practically never happens in the case of samples which have been properly taken and kept by the inspectors pending the appeal to the government laboratory. "The following tables give the results of the analysis of a series of milks analyzed in the fresh state and after the lapse of several weeks. The examination was carried beyond the time at which a milk would be referred to the government laboratory under the Food and Drugs Act, but it will be seen that the changes can be accurately followed and allowed for. The comparison of the corrected nonfatty solids with the solids of fresh milk shows that the variations are not greater than may occur in duplicate determinations of the constituents of a fresh milk."" § 539. Preservatives in Milk. Preservatives in milk, according to most authorities, are wholly unnecessary, and should not be permitted even in the smallest quantities. Annatto, or some other harmless coloring matter, is very commonly used, and the addition of such coloring substance is not, as a rule, complained of; but its object is to conceal inferior quality. Under the influence of preservatives milk may be exposed without sensible injury to conditions which otherwise would render it unsaleable. It may remain sweet to taste and smell and yet have incorporated in it disease germs of various kinds, whose activity may be suspended for a time by the action. of the preservative, but may be renewed before the milk is digested. After hearing evidence from milk traders, the English Departmental Committee on Preservatives and Coloring Matters in Food concluded that the addition of a preservative to milk is not necessary for the purpose of the milk trade, even in hot weather or where the supply of so large a place as London is concerned, and they recommended that no preservatives should be added to milk. "In making this recommendation the committee had special regard to evidence received as to two classes of preservative substances which, under various names, are frequently used as preservatives in milk, viz.: (1) formalin (a 40 percent solution of formic aldehyde) and other preparations of formic aldehyde; and (2) boron preservatives (boric acid, borax, or mixtures of boric acid and borax). The committee considered that the addition to milk of formalin or preparations of formalin, even when the amount which could be detected was minute, was objectionable, on account of the alterations effected by formalin in the character of certain of the constituents of milk and of its ability to interfere directly with digestive processes. Although in the view of the committee boron preservatives might reasonably be employed in the case of certain foods, within defined limits and. subject to a declaration as to their presence and amount, the committee recommended their exclusion from milk alto gether; partly for the reasons above indicated, and partly also in consideration of the immense importance of pure milk for the nutrition of infants, invalids and convalescents, and of the comparatively large quantity of milk which may be taken, particularly by children, in comparison with the other foods in question. Moreover, the committee had evidence 'pointing to an injurious effect of boracised milk upon the health of very young children.' Since the report of the committee was made, the board have from time to time had before them further evidence on the subject, and this supports the conclusions of the committee not only as to the objections to the use of preservatives on the ground of public health, but also as to the ability of milk traders to conduct their business without the use of preservatives. Thus in certain boroughs in London and elsewhere in which milk samples are systematically tested for preservatives, the presence of preservatives in milk, at any time of the year, has been found to be exceptional; and there is evidence to show that a very large number of milk vendors conduct their business without the use of these substances, even where the milk comes long distances by rail."" To put formaldehyde in milk and offer it for sale is to violate a statute making it an offense to fraudulently adulterate, for the purpose of sale, any substance intended for food with any substance injurious to health, where the evidence shows that formaldehyde is injurious to the health of an individual using milk thus adulterated. And where a statute makes it an offense 1 Bell's Sale of Food and Drugs Act (5th Ed.) 221. "As regards formalin and boron preservatives, the Board are advised that the presence in milk of formalin to an amount which is ascertained by examination within three days of collecting the sample to exceed 1 part in 40,000 (1 part of 100,000 of formic aldehyde) raises a strong presumption that the article had been rendered injurious to health, and that the pur chaser has been prejudiced, in the above sense [to an extent that would justify the institution of proceedings for a violation of the statute], and also that a similar presumption is raised where boron preservatives are present in milk to an amount exceeding forty grains of boric acid per gallon." Bell's Sale of Food and Drugs Act (5th Ed.) 224. 2 Isenhour v. State, 157 Ind. 517, 62 N. E. 40, 87 Am. St. 228; St. |