MORTAR, utensil employed by the Indians of America and other semi-civilized races for the grinding or mashing of grains and other substances used as food or for other ends. The Indian mortar naturally had a different name in each tribe, and some of these names were familiar to the whites. A survival of these Indian mortar names is the metate of Mexico (q.v.) derived from the Aztec word metal. The mortar has many forms ranging from a flat stone to a deep receptacle of stone, bone or wood in which the grain or other sub stance is reduced by pounding or grinding to a floury or plastic state. Throughout the area occupied by the Pueblo Indians in the United States, and in Mexico, Central America and the greater part of South America, and especially in Colombia, Venezuela and the Pacific Coast countries the grinding of grain, seeds, nuts, roots and other substances is done on a flat stone, generally rectangular in form. For the most part the grinding is performed by means of a stone muller more or less cylindrical in shape, which is rarely used as a roller, the sub stances being crushed between the metate and the muller by pressure and rubbing. This was the process used throughout the great corn belt stretch from Arizona to southern Chile at the time of the discovery of America; and throughout this vast region it is the process generally in use to-day, more especially among the Indians and mestizos for reducing corn and other substances to a condition for cooking.
Forms of Mortars.— Throughout other parts of North America there were many forms of mortars distinctly different from those in use in the region already indicated, but closely related to one another in shape. Among the Iroquois and other northern and eastern tribes of the United States and parts of Canada the natives made use of wooden mortars hollowed into the top of a block cut from the trunk of a tree. In this hollow, which was of considerable size and depth, the corn or other substance was put, in a dry or wet condition, and pounded into a more or less fine powder or into a soft, semi-liquid mass, by means of a long wooden pestle, with a pounding surface at both ends. The remains of very primitive mortars in many parts of the American continents show the various processes through which the modern mortars have passed to reach their present per fection. Originally a rough unworked flat stone
was used as a grinding surface and an unshaped rounded stone served to do the pounding. From this primitive utensil to the carefully shaped metate of the Mexican or the handsomely carved and hollowed mortar of Alaskan and British Columbian tribes is a long step which bridges a lengthy period of cultural develop ment. In the granite rock of California mor tars in the shape of excavations are frequently found on the sites of old Indian villages. Some of these are very primitive in form, while others, evidently of a much later development, are care fully shaped and seem to follow a regular plan of structure. It is probable that the flat stone metate form and the hollow mortar form both originated in pounding grain on a flat sur face, the two natural methods of preventing the loss of the pulverized grain being to reduce the pounding to rubbing or rolling, and to pound the grain, in a deepish hole, as was done in the California granite rock. The tribes of the great forest area of the North. having no hollow rock beds or stones easily worked, hollowed out the ends sections of tree trunks or sides of logs by means of fire which also hardened the inner surface of the mortars, dried the wood and made them very durable. In regions where stone and wood were not available, bone, rawhide and other materials were converted into mortars for the grinding of food materials. In the whale country some of the races addicted to whale hunting used the vertebra of that animal for mortars. Some of these are still employed. In the Eastern States of the United States primitive mortars made of hollowed but otherwise unshaped boulders are frequently encountered; and similar mortars are formed in California, side by side with other globular mortars, which are evidently but a more artistic development of the boulder form. A further evolution of the artistic form was reached when stones were quarried from the rocky bed, shaped to exact pre-determined form and proportions and frequently decorated with conventional forms, mystic signs or figures of household gods.