either perfectly exact or altogether complete. All wares are divisible into two great classes, viz., transparent porcelain and opaque earthen-ware. PORCELAIN may be natural or artificial. I. Natural porcelain is made from kaolinic clay. It may have-- 1. A pure felspathic glaze, such as porcelain of China, Japan, Limoges, Sèvres, Dresden, Berlin; or, 2. No glaze, such as the biscuit porcelain of China or France. II. Artificial porcelain may be made from alkaline clay, calcareous clay, or felspathic clay. 1. Alkaline clay may have an alkaline glaze, either colorless or colored, or may be biscuit. _a._ Alkaline glaze, colorless--Persia, China, St. Cloud, Limoges, Sèvres, Tournay. _b._ Alkaline glaze, colored--Persia, China, Limoges, Deck. _c._ Biscuit--Old Sèvres statuettes. 2. Calcareous clay has a colorless boracic glaze, as in the case of the English china of Minton, Copeland, and Worcester. 3. Felspathic clay is exemplified in the parian of Copeland, Minton, and Worcester. EARTHEN-WARE is of two kinds--that showing a non-vitrified fracture, and that showing a vitrified fracture. I. EARTHEN-WARE with non-vitrified fracture may have either a transparent glaze or an opaque enamel. 1. Transparent glaze may be plumbiferous or alkaline, and in either case colorless or colored. _a._ Plumbiferous. Glaze, colorless--Faience d’Oiron or Henri Deux ware, Wedgwood, Meakin, Creil, Montereau. Glaze, colored--Palissy, Nuremberg, Minton’s majolica. _b._ Alkaline. Glaze, colorless--Persian faience, Chinese and Japanese faience; Deck, of Paris. Glaze, colored--Haviland or Limoges faience. 2. Opaque enamel is stanniferous, and may be either colorless or colored. Stanniferous, colorless--Della Robbia, Rouen, Moustiers, Delft, Nevers. Stanniferous, colored--Colinot, Parville, Longwy. II. Earthen-ware with vitrified fracture may be either glazed or in biscuit. Of the former, the _Grès_ of Germany, Beauvais, and Doulton may be taken as examples. For convenience of reference, the same classification may be given in tabulated form: CLASSIFICATION OF ALL KINDS OF WARE.