108 ESSAY VI 



SECTION III. ANOTHER METHOD. 



A second method of decomposing arsenic is by means of 

 manganese. Take one part of powdered manganese and 

 mix it in a tubulated retort witb three parts of the above- 

 described muriatic acid. This mixture should fill one-fourth 

 of the retort ; a receiver containing one - fourth of white 

 powdered arsenic, diluted with one-eighth of distilled water, 

 is to be luted on, and the retort put into a sand-bath. The 

 dephlogisticated muriatic acid going over into the receiver is 

 immediately absorbed by the arsenic. Some hours afterwards 

 the arsenic will be dissolved, and two different liquid strata, 

 which will not mix together, be perceived in the receiver. 

 This solution is now to be put into a clean glass retort, and 

 distilled to dryness, and the fire at the end so much increased 

 that the whole remaining mass may be perfectly red hot. 

 In this process also two different liquids go over into the 

 receiver, which do not unite together. 



Of this operation it is to be remarked that the muriatic 

 acid yields its phlogiston to the manganese ; and as the 

 dephlogisticated acid attracts the phlogiston again, wherever 

 it meets with it, very powerfully, it deprives the arsenic of 

 its phlogiston, and hence it reassumes the nature of common 

 muriatic acid. This acid dissolves a portion of the arsenic, 

 and thus forms with it a liquor called "butter of arsenic ; but 

 the other portion of the arsenic that has been decomposed, 

 remains dissolved in the water which was placed in the 

 receiver together with a little muriatic acid, and forms a 

 liquid specifically lighter than the butter, which remains at 

 the bottom. If these two liquids be now rectified, the 

 undecomposed portion of the arsenic rises along with the 

 muriatic acid, and goes over into the receiver in the form of 



