ON THE EXTRICATION OF THE ALKALIFIABLE METALS. 



39 



of wire so constructed as to be easily attached, the crucible was transferred to 

 the interior of the body of the alembic, A. Into the cavity thus occupied, about 

 a dram measure of naphtha was poured. The canopy, A, and body of the alem- 

 bic, B, were then joined, (as represented in Fig. 3,) with the aid of a luting of 

 clay and borax between the grooved juncture and the pressure of the stirrup 

 screw provided for that purpose. 



Fig. 3. 



A communication was made between the alembic and a small tubulated 

 glass receiver, by means of an iron tube thirty inches long, and a quarter in 

 bore. The tubulure of the receiver received the tapering end of an adopter, G. 

 which communicated with a reservoir of hydrogen by means of a flexible lead 

 pipe. The length of the tube prevented the alembic, or receiver, from being 

 subjected to the agitation which results from the condensation of the mercurial 

 vapour. Before closing the juncture completely, all the air of the alembic was 

 expelled by a current of hydrogen, desiccated in its passage by a mingled mass 

 of chloride of calcium and quicklime contained in the adopter. By keeping up 

 the communication with the reservoir of this gas, while subjected to a column 

 of about an inch or two of water, the pressure within the alembic being greater 

 than without, there could be no access of atmospheric oxygen. 



The bottom of the alembic was protected by a stout capsule of iron, (a cast 

 iron mortar, for instance.) The next step was to surround it with ignited char- 

 coal, in a chauffer or small furnace, taking care to cause the heat to be the 

 greatest at the upper part. By these means, and the protection afforded by 

 the mortar, the ebullition of the mercury may be restricted to the part of its 

 mass nearest to the upper surface. Without this precaution, this metal is 



