_Cresylic acid._—Cresylic acid is a generic term now applied to mixtures of tar acids in widely varying proportions. As defined in the literature and as formerly used in commerce the term identified a mixture of ortho, meta, and para cresols in the proportions in which they occur in coal tar. This proportion is approximately 40 percent metacresol, 35 percent orthocresol, and 25 percent paracresol. But in recent years the designation cresylic acid has been applied to all sorts of mixtures of tar acids boiling above 190° C. Practically every maker of synthetic resins, antiseptics, and disinfectants has his own specifications for cresylic acid; it may be any mixture in almost any proportions of the three cresols, the six isomeric xylenols, and the higher boiling tar acids. Imports of crude cresylic acid are understood to be largely xylenol mixtures containing low percentages of the cresols. This loose application of cresylic acid in recent years is due to the increased commercial application of the high-boiling tar acids, especially the xylenols. Under the Tariff Act of 1930 refined cresylic acid, that having a purity of 75 percent or more, is dutiable under paragraph 27 at 3½ cents per pound and 20 percent ad valorem based on American selling price or United States value; while crude cresylic acid, that having a purity of less than 75 percent, is free under paragraph 1651. The provision in paragraph 27 reads, “cresylic acid which on being subjected to distillation yields in the portion distilling below two hundred and fifteen degrees centigrade, a quantity of tar acids equal to or more than 75 per centum of the original distillate.” Under this provision cresylic acid may include an endless number of combinations of tar acids and may or may not contain any of the isomeric cresols. Of the 17 or more tar acids known to exist in coal tar (see table 56), only 8 have boiling points above 215° C. It would seem to be more accurate and more in line with present day usage to have the tariff drop the designation cresylic acid in favor of more definite terms based on composition, such as cresols and cresol mixes, xylenol and xylenol mixes, etc. About 60 percent of our consumption of cresylic acid is in synthetic resins and the remainder in the manufacture of insecticides, antiseptics, disinfectants, and other coal-tar products, such as intermediates for dyes, plasticizers for nitrocellulose, etc. United States production. _The cresols._—There is large production of cresol, metaparacresol, and orthocresol in the United States. Commercial production of paracresol was reported for the first time in 1934, and of metacresol in 1935. Statistics of domestic production and sales are publishable only for the year 1934 because of the small number of producers. The output in that year is shown in table 67. Production has increased appreciably since then. TABLE 67.—_Meta, ortho, and para cresols: United States production and sales, 1934_