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[ 139 ] 



XX. Advanlageoiis Method of preparing Red Oxide of 

 Quicksilver. By J. W. C. Fischer*. 



MoNS has oliserved that. In the preparation of the 

 red oxide of (juicksilver I'rom nitrate of mercury, the whole 

 of the acid is far from being eniployed for the complete ox- 

 idation of the quicksilver, as during the heating of the ni- 

 trate of mercury a considerable quantity of the acid is 

 again obtained. He therefore proposes the employment 

 of a larger quantity of quicksilver than the quantity of ni- 

 trous acid destined for the solution is actually able to dis- 

 solve, as this excess of quicksilver must also be oxidated by 

 the heating of the salt brought to a state of drvness by the 

 escape of the acid. But as the nitrous acid of the shops 

 docs noc always possess the same degree of concentration, 

 I gave a recipe in another workf for finding the proper 

 proportion of quicksilver, which is as follows : If the hot 

 prepared dry nitrate of mercury be rubbed up with Irom 

 one-third to one-half part of metallic quicksilver, and ex- 

 posed in the usual manner to the fire, a proportion that 

 may be cmplu)ed vmder all circumstances will be ob- 

 tained. 



Mr. Schmidt, apothecary of Sonderburc;, in consequence 

 of the before-mentioned observation of C. Mons, made 

 several experiments on this subject without the wished-for 

 success, as he alwavs obtained the excess of quicksilver in 

 a metallic form. The results of my present experiments 

 were quite different, and fully answered my expectation. 



I dissolved in a common heat four hundred parts of me- 

 tallic quicksilver in nitrous acid. To obtain a perfectly 

 neutralized solution, the acid was added only in drops till 

 all the quicksilver was dissolved. The solution was eva- 

 porated lo dryness, in an evaporating dish, and the dry salt 

 was rubbed up with 350 parts of metallic quicksilver. The 

 powder assumed a dark gray colour : but when brought to 

 the consristence of a thick paste by a little water, in order 

 lo complete the union of the metallic quicksilver, the 

 colour became grayish white, and, in general, only five 

 minutes were required to make the metallic (juicksilvcr dis- 

 appear entirely. 'I'he humid mass was moderately dried on 

 a conmion stove, and being put into a retort was exposed 

 to a sudden heat. In three minutes a disenjiajienient of 



■ ^chtrcTi Alli^rtneines Journal fin Cbemir, no. 41, 1802. 

 T Hundliiuh d'Y Pharriiaccutiichtn Piuxii, mcl einci yurredc von D. S. F. 

 ILunLiladt. iSoi. 



oxygen 



