CLAYS 



POTTERY-CLAYS 



THE INDIAN CLAYS 



Detergent. 



Weighting of 

 Fabrics. 



d Haiti, yellow mud is eaten medicinally, and sold under the name Multdni matti. 

 An earth known as sang-i-basri is said to be imported from Persia and 

 used in tonic preparations, owing to the iron which it contains. Saucer- 

 shaped chips of partially baked clay are sold in the Calcutta bazar for 

 eating. Montgomery Martin (Hist. E. Ind., 1838, ii., 167) refers to a sub- 

 stance called khari eaten by women in Bengal. Hooper (Rept. Labor. 

 Ind. Mus., 1905-6, 37-8) gives particulars of 33 samples examined. Silica 

 was the largest constituent, eight samples having 80, twelve 70, and six 

 60 per cent. The analysis showed that these clays had no food value. 

 [Cf. Hooper and Mann, Memoirs As. Soc. Beng., i., No. 12, 249-70.] It 

 is probable that all these clays are nearly allied to fuller's-earth, which 

 in India is employed as an external application to purify the hair and 

 skin, in washing the cloths iised in the manufacture of lac, indigo, etc., 

 as also for weighting fabrics. It is interesting to add that the Institutes 

 of Manu records the punishment to be meted out to manufacturers who 

 add too great a weight to the textiles they produce. The following are 

 said to be the best-known Indian sources of fuller's-earth Colgong in 

 the Bhagalpur Division of Bengal ; the Central Provinces ; the district 

 near Kolath in Bikanir, Dera Ghazi Khan and Multan in the Panjab. 

 Holland says fuller's-earth is mined in the Central Provinces and in 

 Rajputana. 



Fire-clays. Fire-elays. These clays are capable of resisting a very high 

 temperature without fusing or fissuring. They should be as nearly as 

 possible free from lime, iron or alkaline earths, which promote the fusion 

 of silica as in glass-making. In Europe the best clays for this purpose 

 are found below coal-seams, and in spite of the different age of the Indian 

 coal-fields, the underlying clays are found to be available for the production 

 of a fairly good fire-brick material. Fire-bricks are manufactured in con- 

 siderable quantities by Messrs. Burn & Co. at Raniganj, the clay being 

 obtained locally. Promising fire-clays are also found at Jabbalpur, at Jowai 

 in Assam, and at the Chanda, Umaria and Gondwana coal-fields. It is 

 probable that with proper manipulation some of the pottery clays, not 

 hitherto used for the purpose, would afford perfectly refractory materials. 



Pipe-clay. Pipe-clay (namam, kharra, etc.), so called in English from 



its being used for tobacco-pipes. It much resembles China-clay, but 

 possesses more silica. Ball makes no mention of the existence of pipe- 

 clay in India, but Moore (Man. Trichinopoly, 1878, 67) states that a 

 fine bed of it occurs between Terani and Karai. Pipe- clay has also been 

 mentioned as a product of the Madras forests. [Cf. Madras Man. Admin., 

 1885, i., 313.] An anonymous correspondent of The Madras Weekly Mail 

 (April 20, 1905) stated that the clay used in the ornamental pottery of 

 Karigeri in North Arcot was a form of pipe-clay. 



Pottery- Pottery-clays. The pottery-clays of India might be popularly 



clays. assorted according to three degrees of purity, viz. : (a) kaolin, China 



or porcelain clay ; (6) ordinary white or glazed pottery clays ; and (c) red 



or tile and flowerpot clays. The third has perhaps been sufficiently 



indicated above in connection with brick and tile clays, since most average 



Kaolin. good brick clays may be used for unglazed pottery. Kaolin, besides 



being employed for porcelain, is utilised in the paper and soap industries. 



It is sold in the form of large lumps of a white or yellowish-white 



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