The Sale of Food and Drugs Act 1899, which came into operation on the 1st of January 1900, contains several sections relating to the trade in dairy produce in the United Kingdom. Section 1 imposes penalties in the case of the importation of produce insufficiently marked, such as (a) margarine or margarine-cheese, except in passages conspicuously marked "Margarine" or "Margarine-cheese"; (b) adulterated or impoverished butter (other than margarine) or adulterated or impoverished milk or cream, except in packages or cans conspicuously marked with a name or description indicating that the butter or milk or cream has been so treated; (c) condensed separated or skimmed milk, except in tins or other receptacles which bear a label whereon the words "machine-skimmed milk" or "skimmed milk" are printed in large and legible type. For the purposes of this section an article of food is deemed to be adulterated or impoverished if it has been mixed with any other substance, or if any part of it has been abstracted, so as in either case to affect injuriously its quality, substance, or nature; provided that an article of food shall not be deemed to be adulterated by reason only of the addition of any preservative or colouring matter of such a nature and in such quantity as not to render the article injurious to health. Section 7 provides that every occupier of a manufactory of margarine or margarine-cheese, and every wholesale dealer in such substances, shall keep a register showing the quantity and destination of each consignment of such substances sent out from his manufactory or place of business, and this register shall be open to the inspection of any officer of the board of agriculture. Any such officer shall have power to enter at all reasonable times any such manufactory, and to inspect any process of manufacture therein, and to take samples for analysis. Section 8 is of much practical importance, as it limits the quantity of butter-fat which may be contained in margarine; it states that it shall be unlawful to manufacture, sell, expose for sale or import any margarine the fat of which contains more than 10% of butter-fat, and every person who manufactures, sells, exposes for sale or imports any margarine which contains more than that percentage shall be guilty of an offence under the Margarine Act 1887. For the purposes of the act _margarine-cheese_ is defined as "any substance, whether compound or otherwise, which is prepared in imitation of cheese, and which contains fat not derived from milk"; whilst _cheese_ is defined as "the substance usually known as cheese, containing no fat derived otherwise than from milk." The so-called "filled" cheese of American origin, in which the butter-fat of the milk is partially or wholly replaced by some other fat, would come under the head of "margarine-cheese." In making such cheese a cheap form of fat, usually of animal origin, but sometimes vegetable, is added to and incorporated with the skim-milk, and thus takes the place previously occupied by the genuine butter-fat. The act is regarded by some as defective in that it does not prohibit the artificial colouring of margarine to imitate butter.