of some Oxides of Mercury. 125 



verv large quantity of it is pulverized to be converted Into 

 vermilion. This preparation is still a secret among the 

 Dutch. In every work of chemistry, however, the process 

 for obtaining it is described. They merely say that the 

 cinnabar is to be reduced to powder, then washed in water 

 and dried. This method, which M. Paysse often employed, 

 gave him always, indeed, for product a very beautiful red 

 powder ; but it must be allowed that it is inferior in beauty 

 and the splendour of its colour to that manufactured in 

 Holland. 



China furnishes painting with a kind of red sulphurated 

 oxide of mercury in powder (vermilion), much more 

 esteemed than that of the Dutch. It is of a beautiful red 

 colour, with a shade, the splendour of which nothing can 

 equal. For some years^ therefore, the Dutch have endea- 

 voured to imitate it. M. Paysse saw some prepared in the 

 manufactories of that country, the process of which is an- 

 other mystery. This oxide rivals in beauty that of the 

 Chinese. He is of opinion that in a little time it will at- 

 tain to the same degree of perfection. 



As he was not able to obtain any information in regard 

 to the means employed to imitate this particular preparation, 

 and suspecting that the splendour of the Chinese sulphurated 

 oxide of mercury could arise only from the state of oxygena- 

 tion, more or less advanced, in which the mercury may be 

 in that combination, he made the following trial : — He took 

 a hundred parts of Dutch red sulphurated oxide of mercury, 

 and having pulverized them, put them into a glass capsule 

 sheltered from the impression of the solar rays, and covered 

 this powder with some cubic centimetres of pure water, 

 taking care to stir the mixture for a month with a glass 

 tube. At the end of seven or eight days he saw the oxide 

 sensibly change, and assume a very agreeable shade. During 

 about twenty-five days the splendour of the red increased 

 gradually and acquired the utmost beauty. Having ob- 

 served that the matter remained in the same state, and that 

 it no longer underwent any apparent change, he decanted 

 the water, and dried in the shade and in a gentle tempera- 

 ture the red sulphurated oxide of mercury. He compared 

 it in this state, and when very dry, with that of the Chi- 

 nese and that of the Dutch manufactories prepared by their 

 secret process, but did not find any sensible difference in 

 the splendour or beauty of the red ; so that this very simple 

 experiment puts us in possession of a process advantageous 

 to the arts, and particularly that of painting, and which 

 the Dutch will long keep a secret. 



Beingf 



