226 Impraved Method of preparing 



used as a medicine^ it must, ho^^■ever, be allowed that each 

 of these methods is attended with inconveniences, and that 

 the best, even when the materials are of the first quality, 

 does not produce that advantage which might be expected. 

 Without enlarging further on the processes hitherto em- 

 ployed in the pneparati ni of this article, I flatter myself it 

 will not be considered superfluous if I here make known a 

 very convenient method founded on true chemical princi- 

 ples, which, besides its great simplicity, eives a rich and 

 pure product : advantages which must certainly recommend 

 it to the notice of every apothecary. 



In the description of the process I hope I shall be par- 

 doned for being circumstantial, as minuteness is often of 

 great utility, and, in regard to a matter of so nluch simpli- 

 city, can be attended with no hurt. 



Mix one part of pure concentrated nitric acid with four 

 parts of distilled water in a narrow-necked retort ; and 

 having added four parts of pure mercury, place the vessel 

 in warm sand of the temperature of from 120° to 140'^ of 

 Falirenheit. Maintain this heat till the action of the acid 

 on the inetal has apparently ceased ; that is to say, till no 

 niore bubbles arise. 



When the operation has been carried this length, the 

 heat of the sand must be raised to from 200° to 210° of 

 Fahrenheit ; and this temperature must be maintained for 

 three or four hours. Then bring the fluid to a slight state 

 ot ebullition, and, having continued it without interruption 

 for half an hour, pour the whole, boiling hot, into a glass 

 vessel contaiiiing fifty parts of distilled water, with which 

 it will mix exceedingly well by continual stirring. 



In the above operation the following circumstances are to 

 be remarked : 



1st. Should a commencement of crystallization manifest 

 itself during the ciigestion or boiling of the solution, a little 

 warm water must be inmiediately added, to prevent the com- 

 plete crystallization of the matter, because the solution ac- 

 (|uires a strong propensity towards it as soon as too large a 

 quantity of the water has been evaporated during the pro- 

 cess. 



2d. Some metallic mercury must remain at the end of 

 the operation. Should all tlie mcrcurv, however, be dis- 

 solved, it wil' be necessary to add some more of the metal, 

 and to complete the solution as before directed. 



Tiie diluted solution obtained in this manner is then fil- 

 tered, and the mercury remaining on the filler is collected 

 and put into another clean vessel. 



3 rrom 



