192 



CHINA-WARE. 



recipes, which are given in centesimal proportions, may I 

 \>e implicitly relied upon. 



To each 100 Itx. add 1 ox. of best cobalt blue, ground. 



The above are only mixed together, to constitute the clay. 



Other china bodies have much of their substance fritted. 

 This process is adopted to chemically combine all the prin. 

 cipal components together, by subjecting them, during 

 some hours, to a gradually-raised temperature ; and which, 

 dissipating the aqueous, gafeous, carbonaceous, and other 

 volatile ingredients, effects their complete fusion, and ren- 

 ders more readily obtainable all the properties of the 

 several minerals in the compound. Wherefore, the fusible 

 components must be in definite proportion to the others ; 

 and, unless this process was employed, there is a possi- 

 bility of the high heats of the baking volatilizing the alkali 

 before complete fusion ensues. The J'ritt is ground (simi- 

 larly to flint) into an impalpable powder, in which state it 

 is mixed with the other components that do not require to 

 be fritted, in such proportions that there may continue a 

 state of tenacity to bear the manipulations of throwing, 

 moulding, or pressing. 



The four annexed recipes are in common use by the 

 persons whose names are affixed to them : 



(1) Fritt. Cornish stone, fifty; bone ash, fifty: grind 

 and mix for body, 1'ritt, seventy-five; dry flint, five; blue 

 clay, 20. J. Mare. 



(2) Fritt. Cornish stone, forty; bone ash, forty ; cullett, 

 twenty : grind and mix for body, fritt, eighty ; blue clay, 

 twenty. Bake very highly. J, Clawes. 



(3) Fritt. Cornish stone, twenty-two ; flint, twenty- 

 eight ; cullett, twenty-eight ; white lead, twelve ; salt, 

 three ; borax, six ; blue calx, one : grind and mix for body, 

 fritt, forty ; china clay, forty-eight ; blue clay, twelve. 

 J . Penningto*. 



(4) Fritt. Cornish stone, forty ; bone, twenty-nine ; cul. 

 lett, twenty-two ; borax, nine : grind and mix for body, 

 fritt, forty-eight ; china clay, thirty -eight ; blue clay, four- 

 teen. JF. Marsh. 



The constitution of these bodies intimates a more dense 

 and compact texture than the preceding ; and the attempt 

 itself is a most useful lesson in chemistry, when properly 

 and steadily pursued. 



The china now most esteemed for all the properties of 

 the Japanese, and superior beauty of colour, has felspar 

 among its components, in the proportions below : 



Stain with blue calx, as previously directed. 



When such an excess of bone earth is present, as some 

 of the recipes exhibit, there need not be any surprise that 

 even very excellent felspar porcelain (to appearance), fre- 

 quently fails on sudden rise of temperature. 



Some china of this kind, very superior in quality, is 

 made by part of the components being prepared in fritt. 

 The two recipes annexed, exhibit the components and 

 their proportions : 



(1) Fritt. Felspar (greenish), seventy-five; borate of 

 soda, twenty ; muriate of ammonia, five. Body. Fritt, 

 fifty, china clay, fifty ; or, fritt, fifty; china clay, thirty; 

 bone, twenty. 



(2) Fritt. Felspar (greenish), sixty ; borax, twenty-five ; 

 nitre, five; sal-ammoniac, ten. Body. Fritt, forty-five; 

 china clay, forty ; bone, fifteen : or, fritt, thirty-five ; china 

 clay, thirty; bone, thirty. 



A particular kind, called stone china, is compounded 

 (mostly for jugs and toilet services) of the following com- 

 ponents : 



TLe ironstone china is formed by introducing ground 

 clay from the smelting furnace, in the proportion of twenty- 

 eight for seventy-two of No. 3 or 8, carefully blunging the 

 fluids together. 



Ory bodies. That class of wares which undergo incipient 

 vitrcsceuce, without any glaze on their surface. Of this 



species, the red and the cottage brown are compounded n 

 below: the materials being well levigated, finely lawueu, 

 and carefully fired. 



Many flower pots and lustre jugs are formed of 3 and 4 

 red; and 4, 5, brown. Another kind of red is seen in the 

 porous body, used for coolers of water, butter, and wine, 

 and called alcaraxas in Spain. These articles are b:i*i.t 

 in a very slow part of the oven ; and, after being inirnrrsi <t 

 in water till saturated, on any substance being placed 

 therein, the cold caused by evaporation reduces the tem- 

 perature of that substance to a most palatable state. Tint 

 components stated as forming those used in Spain, are 

 sixty parts of compact mar) (Jamieson II. 194), and 

 thirty-six and a half of decomposed common hornblende. 

 But in Staffordshire, the following are the components : 



The marl must be well weathered (several months ex- 

 posed to the action of the atmosphere), and the fluid mix- 

 ture passed through a fourteen lawn ; after which the other 

 components are added. The articles are baked in the top 

 of the oven when baking glaze. 



The several shades of drub are thus compounded : 



The cane (much similar to baked pastry) supplies many 

 articles, from moulds likewise employed for jasper and 

 pearl. The components are : 



The Egyptian, best black, or vitrified basalts, is formed 

 of these components : 



The pearl is formed of these components, and is baked 

 in the first ring of the biscuit oven, carefully raised and 

 cooled : 



' 



Or (1) Frill Flint Glass, 76 ; Red Lead, 22; Borax, 2. 



(2) FVitf Do. 62 : , Do, 89; Do. 4; Nitre, 8; Flint. <;. 



(3) Frill Do. 80; Do. 20; 



(4) Frill Do. 70; Do. 24; 



Do. 6. 



The jasper is compounded either by fritt, or without it ; 

 mt the components require to be ground well together, be- 



fore they are evaporated on the slip kiln. 



