UNDER THE INFLUENCE OF CHEMICAL ACTION. , 
o 
o 
lip E. Below C the glass tube was drawn out to a fine nozzle, and the lower end of 
the tube about C was silvered, and the silver coating connected through to the alloy 
inside by a platinum wire sealed through the glass. The object of this was to 
maintain the outside of the tube at a definite electrical potential and to prevent 
trouble due to charges developing on the glass surface. Matters were so arranged 
that the nozzle was about a millimetre above the centre of the copper sphere F. This 
was attached to a stout wire supported by glass and connected through to the outside 
by the platinum seal shown at H. Part of the weight of the sphere was taken by a 
copper pin which butted into a small hump blown in the tube wall at M. The copper 
sphere, which was 5 cm. in diameter, was provided with openings in front and behind 
as indicated at C4 for the purpose of throwing a powerful beam of light of suitable 
frequency on to the drops which formed at the nozzle. The light was supplied by a 
Westinghouse Cooper-Hewitt quartz mercury vapour lamp and admitted through a 
tube sealed into the main bulb. This tube is at right angles to the plane of the figure, 
which does not show it. The end was ground flat and closed with a thin quartz plate 
cemented on with sealing-wax. The copper electrode F was provided with holes at the 
top and at the bottom. The drops fell through the lower hole into the bulb J, which 
was closed by a stop-cock below K. The alloy in J was connected to earth by the sealed 
platinum wire K. When a sufficient amount of the alloy had collected in J, dry carbon 
dioxide or nitrogen could be admitted at N, and the alloy forced back into the reservoir 
by a system of tubes and stop-cocks not shown. In this way a sample of the alloy 
could be used a considerable number of times without dismembering the apparatus. 
The side tube N led to the phosphorus pentoxide bulb, the MacLeod gauge, the gene¬ 
rator of inert gas just referred to, the pumping system (Gaede mercury pump and Geryk 
backing pump), and the generator of the chemically active gases under consideration. 
This consisted of a closed vertical tube about 5 mm . in diameter provided with a stop¬ 
cock and connected with a point near N through about a metre of similar glass tubing 
running horizontally. The gases dealt with were carbonyl chloride (COOL), chlorine 
(Cl 2 ), hydrochloric acid (HC1) and water vapour (H 2 0). The three first were 
condensed into the generating tube by means of liquid air in a thermos vessel 
placed outside it, and the amount released into the apparatus could be varied by 
manipulating the height of the liquid air outside the generating tube. The water 
vapour was supplied from mixtures of water and sulphuric acid or from crystals of 
CaCl 2 6H 2 0. 
Most of the experiments deal with C0C1 2 - Except in the most recent experiments 
this was prepared by boiling a mixture of 20 parts chloroform, 50 parts potassium 
bichromate and 400 parts sulphuric acid in a flask with a reflex condenser attached. 
The gas was freed from hydrochloric acid by bubbling through water, from water by 
bubbling through sulphuric acid, and from chlorine by passing through a U-tube con¬ 
taining small pieces of antimony, and then condensed in a freezing mixture of ice and 
salt. For the most recent experiments we have been able to secure a pre-war sample 
b 2 
