[ 4 ] 

 ir. Reflexions on Prujfiats. By I. M. Haussmann 



T< 



fix on ftuflTs with fuccefs the metallic pruffiats, it was 

 neCeflary to examine with care the refults ariling from the 

 mixture of metallic folntions with the pruffiats of pot-afh or 

 01 lime. The moft interetiing information which I procured 

 bv my experiments is as follows : — 



The red oxyd of mercury fubjefted to the aftion of the 

 liquor of pruffiat of pot-afh or of lime, acidulated by the ful- 

 phuric acid, did not produce blue, but was transformed gra- 

 dually into yellowifli fulphat of mercur}" : next morning, after 

 an addition of the muriatic acid, the change took place in 

 an inftant, and I obtained a blue Exceedingly brilliant. Hav- 

 ing, inftead of the fulphuric acid, employed the muriatic, the 

 red oxyd was di(]blved, and the liquor became tranfparent, of 

 a bad blue colour, which became gradually brighter as it 

 was precij itated. The red oxyd of mercury, diflblved firft by 

 the nitric acid in excels, to which was added prufliat of pot- 

 afh or of lime, furnifhed alfo a blue. The operation is How 

 when the red oxyd is ufedAvithout difTolving it, and when 

 you confine yourfelf to acidulating the prufTiat with the nitric 

 acid. An aqueous folution of the oxygenated muriat of mer- 

 cury, mixed with a folution of prufliat of pot-afli or of lime, 

 acidulated by the muriatic or nitric at id, gives alfo a very 

 beautiful blue. 



In all thefe procefTcs of mercurv, and particularly the lafl, 

 a part of this oxygenated fubflance remains in folution, and 

 refembles the liquor obtained by deltroying the colour of the 

 prufliat of iron by means of the red oxyd of mercury and of 

 water. The oxyd of filver is changed with more difficulty. 

 I diluted with water a nitric folution of that metal ; and when 

 I hit thejufl proportions of ihe prufliat of pot-afli, and the 

 fulphuric or muriatic acid, I obtained, by fliaking from time 

 to time, the mofl beautiful blue in the fpace of twenty-four 

 hours. The liquid arfenic acid, mixed with prufliat of pou 

 afb or of lime, acidulated with fulphuric acid, gives a very 

 beautiful blue. 



• Frbm Journal 4e Pbyf^iuc, an . 7. 



A folutb^ 



