2 82 Obfervaliom on Naples Yellow, 



After Fougcroux's paper was printed, De la Lande pub- 

 lifhed a receipt which he had received from the well- 

 known prince San Severo, and in which lead and antimony 

 only are employed ; but no mention is made either of alum, 

 tartar, or any othe"r fait *. 



The fixity of this pigment, a property in which lead ochres, 

 when ui'ed alone, are deficient, is afcribed by Fougcroux to 

 the antimony and alum. The latter, perhaps, may not be 

 neceffary, but the addition of the former is indifpenfible. It 

 is well known that the glafs of antimony has a hyacinth co- 

 lour, and that with red lead and flint it produces glafs of a 

 gold colour f. 



Artifts generally complain that this pigment often fails in 

 its application, becaufe they cannot always procure it of an 

 equal quality. This difference arifes in all probability from 



As dictionaries, and particularly thole of the Italian language, 



•*rc ii. general deficient in regard to fcientific cxpreifioiis, it would be 



a great fervice to the public if fome man. of learning would collect 



pLiiii all thofe which relate to chcmiltrv and mineralogy- At any 



-.ate translators ought to follow the good example let them by M. Leon- 



hardi. 



,; I fhall liere give the whole receipt as it ftands in the laft part of 

 the newelt edition of Voyage en Unite, par De la Lande. Paris, 1786, 

 9 vol. izmo, p. 504 -• Take lead well calcined and lifted, with a third part 

 of its weight of antimony pounded and lifted alfo. Mix thefe fubftances 

 well together, and rift them again through a piece of filk. Then take 

 large Hat earthen difhes, not varnifhed, cover them with white paper, 

 and fpread out the powder upon them to the depth of about two inches. 

 Dace thefe dilhes in a potter's furnace, but only at the top, that they 

 mav not be expoled to too violent a heat. The reverberation of the flame 

 will be fufficicnt. The difhes may be taken out at the fame time as the 

 earthen-ware, and the iubfrance will then be found hard, and of a yellow 

 colour, ft is then pounded on a piece of marble with water, and after- 

 v aids dried for uft. This is what is called Naples yellow. 



j I'o this fubjefl belong the experiments of Lewis, who, though he 

 i' fully examined all thofe fubltances which feemed proper for colouring 

 makes, however, no mention of Naples yellow. See his Pbi/ofo- 

 bbical of the Art!. 



9 the 





