=Materials Used in the Manufacture of Oleomargarine.=--_Neutral Lard._--One of the principal basic components of oleomargarine is neutral lard or lard stearin, the properties of which have already been described. Beef fat stearin is another basic ingredient of oleomargarine and is the stearin derived from tallow or tallow itself. Beef fat has a higher melting point than lard and beef fat stearin a still higher melting point than the tallow. Hence it forms an ideal ingredient with which to mix the oily components which enter so largely into the manufacture of oleomargarine. The beef fat or beef fat stearin is easily distinguished by means of the microscope. It forms beautiful radiated fan-like crystals, the characteristic appearance of which is shown in Fig. 9, page 67. _Cottonseed Oil and Cottonseed Oil Stearin._--These are also important ingredients of oleomargarine affording the oily or more liquid constituents which, when mixed with the lard and stearin above mentioned, form a compound the melting point of which is slightly above that of butter and sufficient to maintain it in an unmelted state even in warm weather. The quantities in which these different ingredients are used vary greatly in different manufacturing establishments and depend largely upon the location where the oleomargarine is to be used. When manufactured for tropical or subtropical regions larger quantities of stearin are employed than when used in temperate zones or for winter consumption, in which case larger quantities of cottonseed oil and cottonseed oil stearin are employed with the mixture. After the fats are mixed it is usually the practice to churn them with milk in order to give a flavor of butter to the product. In some cases the yolk of eggs is mixed with oleomargarine, as it is claimed that they impart thereto a firmer and more homogeneous structure which renders the mass better, especially for cooking purposes. All the ingredients which are used in the manufacture of oleomargarine are made known and recorded in the books of the Commissioner of Internal Revenue and thus it is a product which it may be said is strictly under government supervision.