AND STATICS UNDER THE INFLUENCE OF LIGHT. 
349 
Before the chlorine was prepared for the experiment the tube containing cupric 
chloride, (7), and the tube (8), with phosphorus pentoxide, were connected with the 
tube (20) leading to the quartz vessel (II), and heated and exhausted till the pressure 
was reduced to not more than 0’01 millim In this way the air was first expelled from 
all vessels and from the cupric chloride. The tap connecting all these parts with the 
mercury pump was then shut, and 1 or 2 centims. of the tube (7) gradually heated 
nearly to red heat and chlorine slowly evolved. When the manometer indicated 
that the pressure of the chlorine was about 10 centims., the heating of (7), and with 
it the formation of chlorine, was stopped. After removing the chlorine by means of 
the removable pump, fresh chlorine gas was admitted. This process was repeated to 
expel the last trace of air, when chlorine was again introduced and sealed up in the 
tube. 
B. Preparation of Pure Carbon Monoxide. (See (9), (10), (13), (14) and (15) 
of figure (1), Table I.) 
Carbon monoxide gas was prepared from sodium formate (35 gr.), and a mixture 
of concentrated sulphuric acid (200 gr.) and water (100 gr.), the proportions 
given by Lord Rayleigh. Carbon monoxide is produced when the mixture is 
heated, and its formation is stopped when the mixture is cooled down to the ordinary 
temperature, so that the same solution can be repeatedly used for the production of 
carbon monoxide. 
The experiment was so arranged that neither the vessels nor the liquids used for 
the reaction contained any air. The sodium formate was introduced into (10) 
through the neck (25), the stopper of which was so well ground that when covered 
with vaseline it could stand a vacuum for any length of time when the pressure of 
the carbon monoxide in the vessel was one atmosphere. Vessels (9) and (10) had 
the U-tube (13) containing pieces of caustic potash, the long and wide tube (14) 
containing phosphorus pentoxide and the carbon monoxide reservoir (15), as well as 
the tube (R) between (16), (6) and (17), the purpose of which was to protect the 
carbon monoxide in (15) from contamination with air, were all heated and completely 
exhausted. During this taps (11) and (16) were open, and taps (24), (26) and (17) 
were turned oil. 
The air had next to be removed from the channels of the taps (24) and (26). This 
was affected in the way shown in figure (4). After all the vessels (9), (10), 
(13), (14), (15), &c., were evacuated to a high degree, a capillary tube ( t') with the 
tap (T) at one end and a piece of india-rubber tubing (R) at the other drawn-out 
end, was pressed tightly into the tube of the funnel of (10), and another similar 
one into the funnel of (9). (T) was turned off, (24) opened. After this the same 
was done with tap (26). Since the volume of the channels in the taps (24) and (26) 
and the space above them is perhaps only 0'3 cub. centim., while the volume of all 
