The original "chewing gum" was spruce gum, the exudation of the cut branches of the spruce or fir tree. Later, pure white paraffin wax, variously flavored, took its place, but only in its turn to give way to the "chicle" now almost exclusively employed.

Though its employment in the manufacture of chewing gum is of comparatively recent date, chicle was used by the Indians prior to the days of Columbus as a means of quenching their thirst. It was first commercially imported as a substitute for rubber, but its peculiar suitability for chewing gum has resulted in the entire product being consumed by that industry. In 1885 the United States imported 929,959 pounds of chicle. The growth of the chewing gum industry is shown by the importation of nearly 5,500,000 pounds for the year ending with June 30, 1910.

The trees are "tapped" during the rainy season. The sap, or juice, as it exudes has the appearance of milk, but gradually changes to a yellow color and is about the thickness of treacle. The tree drains rapidly, the full supply of "milk" being generally obtained within a few hours, but an interval of several years usually elapses before it will yield a fresh supply. The milk differs from the juice obtained from the sugar maple, for example, in that it is not the life sap of the tree, and the flow varies greatly, some trees which show full life yielding much less than apparently poorer specimens. "Crude chicle" is obtained by simple boiling and evaporation of the milk, accompanied by frequent kneading. The product, as pressed in rough molds, is of a light gray color.

The bulk of the crude chicle manufactured is shipped in blocks to Canada, where it is further evaporated and carefully refined prior to importation into the United States. When the chicle arrives at one of the chewing-gum factories it is immediately turned over to the grinding department. It comes from Mexico in cakes, varying in size from twelve- to eighteen-inch cubes; these are a putty color, but in composition chicle is porous and brittle, particularly after it is thoroughly dried. In the cubical form it is said to contain from twenty-five to thirty per cent moisture. After it is ground and dried it is practically free of moisture, but one of the most difficult problems which the manufacturer faces is to thoroughly dry chicle before he proceeds to treat it for its introduction as the base of chewing gum.

The cubes are broken by a large steam hammer into irregular-shaped pieces weighing from a few ounces to a pound. These chunks are then run through grinding machines, which reduce the chicle to a coarse meal. Sometimes this breaking and grinding is done in Mexico, but the duty on ground dried chicle is five cents per pound more than upon cube chicle.

Chicle meal is dried upon frames in a special drying room, which is kept at a temperature of 80° F. An electric blower exhausts all of the moisture from the air. The pure meal is then transformed into a thick syrup under intense heat and passed through a filtering machine, one of the latest and most expensive pieces of machinery employed in the entire manufacture of chewing gum. This machine has practically solved the perplexing problem of separating impurities and foreign substances from chicle. Before the filterer was invented it was almost impossible for the manufacturer of chewing gum to produce gum entirely free from particles of grit.

During the process of filtration the chicle is also sterilized, and comes from the machine as pure as distilled water.

It is next passed to the cooking department and placed in huge steam-jacketed kettles, which revolve continually and thus keep the chicle from scorching. While

*Illustrations by courtesy of the Common Sense Gum Co. Story by courtesy of the American Chicle Co. and the Common Sense Gum Co.

A Battery of sugar-Coating Machines.

A Corner of the Scobing Room.

The Laboratory.

Wrapping and Packing Department.

it is being cooked in these large kettles sugar is added, and as soon as the gum is done it is placed in a kneading machine. It is now about the consistency of bread or cake dough, and after being kneaded and cooled, flavor is added.

Peppermint, spearmint and other oils used are triply distilled and absolutely free of all impurities. The orange oil comes from Messina and is always the product of the very latest orange crop.

From the kneading machine it reaches a sizing table, to which are attached heavy rollers for reducing the mass of gum to a strip about a quarter of an inch in thickness and twelve inches wide.

At this stage it will be seen the gum begins to take on a ribbon shape. As it comes from the first series of rollers, it is cut into short lengths sprinkled with powdered sugar, and these short lengths are passed in sticks about two feet high on to a second series of rollers. Under the second rollers each short length of gum is once more reduced in thickness and extended in length.

The surfaces of the second rollers contain knives running lengthwise and around. These knives partially cut the gum to its final size. The thin sheets are then sent to another drying room. They remain in this room from twelve to forty-eight hours, according to the season of the year, and are then ready for the wrapping machines.

Machines have also been invented which stamp out little nuggets of gum. To be finished these pieces are sent to a long room containing a line of twelve large white kettles, each on a separate base. It is these machines which coat the nuggets with snowy sugar. The kettles revolve until a sufficient coating of the liquid sugar has adhered.

The chewing gum wrapping machine is considered by machinery builders to be one of the most ingenious automatic manufacturing machines in use. It is about the size of an ordinary typewriter desk and is operated by one girl. She receives the thin sheet of partially cut gum from the last drying room. The machine operator drops the slabs of gum into a feeding chute. Each slab is here automatically wrapped in wax and silver-foil papers. These papers are fed from rolls, as printing paper is fed to a newspaper press.

As the slabs are wrapped they slide into a pocket. When five of them are finished, two steel fingers remove them and put on the final outside wrapper. The complete, wrapped packages of five slabs slide along a little runway into boxes.

The same girl who feeds the gum into the wrapping machine closes the lids of the boxes and places them on a packing table by her side. When the packing table is filled with boxes a boy removes it to the shipping room, where it is crated and forwarded to the wholesale dealers.