300 Extrication of the Alkalijiahle Metals, 



The best index of the success of this process is the evohition 

 of chlorine; since in proportion to the quantity of this principle 

 extracted at the anode, must be the quantity of calcium separated 

 at the cathode. During my operations, chlorine was evolv^ed so 

 copiously as to tinge the cavity of the innermost bell with its 

 well known hue. Hence, when the evolution of chlorine ceases 

 to be very perceptible, the amalgam should be extricated from 

 the apparatus, and separated by a funnel and the finger from the 

 solution of chloride, and immediately subjected to distillation. 



It has been mentioned, that in the electrolytic process above 

 described I resorted to the alternate action of two deflagrators. 

 This was effected by making the negative poles of both commu- 

 nicate with the mercury in capsule D, while the positive poles 

 communicated with some mercury in capsule L. For a descrip- 

 tion of the deflagrators employed, I refer to the American Philo- 

 sophical Transactions, vol. v, or to this Journal, vol. xxxii, p. 285, 

 as those which I employed were of the kind there described. 



I have found great benefit to arise from Mr. Sturgeon's expedi- 

 ent of amalgamating the surfaces of the zinc ; which Faraday 

 has represented as giving, to a great extent, the properties of a 

 sustaining battery. Agreeably to my experience, it renders the 

 plates less liable to be encrusted with suboxide of zinc and cop- 

 per, which always impairs the energy of a voltaic series. 



Distillatory Apparatus and Process. 

 A quantity of the amalgam, weighing Fig. 2. 



about three thousand grains, was intro- '""" -^ ^"3^ 

 duced into an iron crucible. Of this cru- i^|y^^a::|i.:,|| y^ 

 cible a section is represented by Fig. 2, H ^^^^ g 

 which was forthwith closed by a capsule pl^^Hp/ 

 seated in a rabbet, or groove, made on 'H^^M 

 purpose to receive it. The capsule being ^ ' 



supplied with about half a dram of caoutchouchine, was then 

 covered by the lid. In the next place, by means of a movable 

 handle, or bail, 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 meas- 

 use of naphtha was poured. The canopy, A, and body of the 

 alembic, 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. 



