372 Method employed in Spain 



Thefe veffels, which are of different forms and fizes, ara 

 manufactured in various parts of Spain, and are generally of 

 a greyilh white colour. The moft celebrated place for this 

 fpecies of pottery, and that from which all the veffels of this 

 kind ufed at Madrid are brought, is Anduxar in Andalufia. 

 The earth employed for making them is procured on the 

 banks of a rivulet called Tamuforo, which is fituated at the 

 diftance of a quarter of a league from the above town. 



The ufe of thefc vafes was introduced into Spain by the 

 Arabs. They are full ufed in Egypt, as well as in different 

 parts of Africa; and are known in the Eait Indies, Syria, 

 Perfia, China, and other part3 of Afia. 



It is aftonifhing that thefc vafes were never introduced by 

 the Arabs into Sicily. I never faw any of them in any 

 part of that ifland. This lingular fa£t proves, that the 

 fimpleft and moft beneficial ufages are rarely imitated by 



mifts, during the heats of fummer, caufe, in fome minutes, the congela- 

 tion of water incloftd in a (mail glafs ball covered with a cloth dipped in 

 ether, care being taken to renew it in proportion as it evaporates. ]t is 

 well known that eoldnefs may be efiefted by liquors much lefs volatile 

 than ether, either by expofing the vale, the fur face of which has been 

 moiftened with them, to a current of air, or by Twinging it round a point of 

 ■ fufpenfion, which by moving it through the air ferves to favour the Solu- 

 tion of the vapour in the. atmofphere. From thefe principles it will be 

 readily conceived on what depends the property of the alcarrazas above 

 mentioned. On being expofed to the open air, or rather to a current of 

 air, the water they contain becomes cool in a little time, and to fuch a 

 fenfible degree, that in Summer, when the thermometer ftood at tjg x ° F- 

 in the Shade, at Madrid, the water has been known to defcend to the 

 temperature of water preftrved a considerable time in a cellar. Thefe 

 vafes, however, cannot be long ufed, unlefs care be taken to fill them only 

 with very pure water, and fuch as is little charged with the fulphat of 

 lime (frlenite). Turbid water foon elofes up the pores even of filtering 

 paper; and the fame effsft will be produced by water that holds in folution. 

 fulphat of lime, becaufe the water abandons it in proportion as it unites 

 with the air in a ftate of vapour. To open the pores, clofed up by earthy 

 fdts, it will be Sufficient to keep thtfe vafes for fome moments in boiling 

 >va:er. Ei>jt. 



other 



