148 COLOURS OBTAINED FROM METALLIC OXIDES. 



The impalpable Laftly, I repeated the fir ft experiment by wauYmg fome 

 mcuds, °* thC emerv verv & ne > and flightly ground with it a plate of zinc on 

 another of copper, and then wafhed them in a glafs of clear 

 water. It was feveral hours before the fediment had all fallen 

 to the bottom of the glafs ; but when it had, it acted nearly 

 with the fame power as in the firft cafe, and continued to acl: 

 quite as long *. 



.If, Sir, you mould judge the above account worthy of 3 

 place in your Philosophical Journal, I fhall confider myfelf 

 very much obliged by its infertion. 

 I am, Sir, 



Your obedient humble fervant, 

 Wm. WILSON. 



III. 



On the Colours obtained from Metallic Oxides, and fixed by 

 Means of Fufion on different Vitreous Bodies. By Alex. 

 Brongniart, Director of the National Manufactory of 

 Porcelain at Sevres, Engineer of Mines, #c. 



{Concluded from Page 101.) 



Concerning the Red, Rofe, and Broun Colours obtained from lron. % 



Red colours from A HESE colours are made from red oxidated iron prepared 

 the oxide of iron. with nitric ac j d y he oxides are ca l c j nec i ftjlj more by expofing 



them to the action of fire. If too much heated, they change to 



a brown. 

 Cbmpofition. Their flux is compofed of borax, fand, and minium in fmall 



quantity . 

 They may be Thefe are the oxides which afford the rofe and red colours 



fobftitiited for that may be fubftituted inftead of the fame colours made from 

 'oxide of gold. If properly applied on hard porcelain, they 



never change. I have made rofes with thefe colours, and there 



* Thefe galvanic facls appear toconftitufe one of the cafes detail* 

 ed with larger pieces of metal, and obfeurely explained by Fabbroni 

 in his curious paper in the Philof, Journal, quarto feries, IV. 120. 

 — W. N, 



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