FATS. 1S1 FATTORI. The fats ;irc lighter than water; when brought in contact with paper or fabrics they leave a translucent grease-spot, which is generally very difficult to remove, though it can sometimes be washed out with ether, benzine, chloroform, oil ■of turpentine, and other organic liquids in whii b the fats are soluble. To determine the amount of fat in milk, cheese, or any oilier mixture sub- mitted for examination, the analytical chemist dissolves out the fat with ether, separates the ethereal solution from the other ingredients, evaporates it. dries the residue, and weighs the [aire tat thus obtained in a suitable dish. Fats have the peculiar property of forming emulsions with water, in which the minute globules of fat often remain in suspension for a very long lime; milk is such an emulsion. To emulsify fat arti- ficially, it is melted, if hard, ami simply shaken up with water in which some carbonate of soda lias been dissolved. licsiiirs serving as a necessary ingredient of food, fats are applied industrially to many useful purposes. They are often used as fuel and as illuminants, ami very extensively for the manu- facture of soap and candles. Formerly they were much used also as lubricants; in this application, however, they have been largely replaced by oil derived from Russian petroleum. To obtain the fat, the suet from the animal body is pressed between warm plates or kneaded in muslin bags placed in hot water: the fat melts and is readily separated from the animal mem- branes. Or else the fat is dissolved out with ether, in which the membranes are insoluble. An- other process sometimes employed consists, on the contrary, in dissolving the membranes with di- lute aeiil or alkali, which leaves the fat unat- taeked. The crude fat may be purified by treat- ment with sulphuric acid. Fats are composed of carbon, hydrogen, and oxygen. Their chemical nature was thoroughly explained by the French chemist Chevreul as far back as 1811. Chevreul showed that fats arc combinations of ordinary glycerin and certain so-called fatty acids. Glycerin is a tri-atomic alcohol; that is to say, like the hydroxide of a tri-valent metal (such as ferric hydroxide), it acts like a weak base and is capable of combining with three molecule equivalents of a monobasic acid (such as ordinary acetic acid). The combination of an alcohol and an acid is called in chemistry an rxtrr. or ethereal salt. The esters of glycerin and stearic, palmitic, and oloei'c acids are called, respectively, tri- stearin, tri-palmitin, and triolein. The vari- ous fats are mixtures mainly of these esters or 'glycerides,' containing them in varying rela- tive quantities. Fats, like tallow, containing a large proportion of tri-stearin and tri-pal- mitin are comparatively hard; on the contrary, lard and similar fats, which are soft and pasty, are found to contain a high percentage of tri- olein. The color, state, consistency, etc.. of fats vary with the source from which they arc de- rived. The fat of carnivorous animals has a peculiar disagreeable odor, and is not so hard as that of herbivora. Tinman fat contains, be- sides tri-palmitin. tri-olei'n. and some tri-stearin, also a yellow substance resembling bile by its odor and bitter taste. The animal secretions all contain a certain amount of fat; ear-wax, for instance, has been shown to contain some tri- stearin and some triolein. Tlnttrr contains about
- 7 per cent, of fat, including a considerable
amount of Irihutyrin I I lie ester oi glycerin and butyric acid) ; oleomargarine, prepared from the be i hcci tallow, differs but slightly in uposi- lion from butter.
lien exposed to the act ion of steam heati d
to a temperature of 4110 ' I', (about 200 I I , all fat-, ami fatty oils are decomposed into their chemical constituents. The same action takes place in the presence of moisture, though much e slowly, at ordinarj temperatures (the ran ciditj of fat i- ilue to the separation oi free acids and may, therefore, he removed by dissolv- ing out the acids with water). A similar decom- position lakes place in the animal organism; steapsin, one of the pancreatic ferments, splits up and emulsifies fat in the proce oi digestion. Even more readily than with hot steam, and at a much lower temperature, is the d position of fat effected with caustic alkalies. When fats are treated with sodium or potassium hydroxide, the metal takes up the acid of the fat, forming the salts known in common life as soap, while the glycerin of the fat is set free. The process is extensively employed in the manufacture of soap, and is therefore generally spoken of by chemists as the saponification of fats. See Esters. In the animal organism, or when heated with free access of oxygen, fats are burned (oxidized) completely, yielding, like other compounds of carbon, water and carbonic acid. But when they are burned incompletely, as sometimes in care- less cooking, a number of combustible gases are produced, including the vapors of acrolein, to which the irritating odor of superheated fat is due. See Oils. FATSHATJ. A great trading mart and manu- facturing centre in the Province of Kwang-tung, South China, second in importance to Canton tq.v. I. It is one of the five chin or great marts of the country, the others being King-tch chin, in Kiang-si; Siang-t'an. in Hu-nan; Hankow, in Hu- peh; and Singan-fu, in Shen-si' It i- situated on the left bank of the Chu-kiang, or Pearl River, near the mouth of the North River, and 15 miles by water west by north of Canton. It has a popu- lation of 500.000. Its industries include the manufacture of cloth, silk, paper, embroideries, porcelain, rattan, bamboo, and brass wares; but it is especially noted for its iron and steel manufac- tures, and has been called 'the Birmingham of China.' Whole cargoes of old horseshoes and old iron of all kinds are annually shipped to it. from Great Britain for use in this industry. Fatshan also does a large business in cassia, grain, oil, and timber. The town is facilitating the immense traffic with Canton. It has a tele- graph station, two churehes, and the Wesleyan Hospital, with accommodation for 1000 patients. It is said that before the expulsion of the Jesuit and other missionaries the Christians of Fat- shan numbered 10,000, but no trace of them is now to he found. FATTORI, fat't.Vre. Giovanni (1825—). An Italian painter, born in Livorno. He was a pupil cf Giuseppe Bezzuoli in Florence, studied further in the academy there, and in 1859 exhibited his first important work. "The Battle Near Magenta" (Florence Academy). In 1877 he became a pro- fessor in the cailemy of Florence and a member of that of Bologna. Other paintings of his are: "The Battle Near Madonna della Scoperta"
