350 
DR. MEYER WILDERMAN ON CHEMICAL DYNAMICS 
the vessels is about 1500 cub. centims., the pressure in all the vessels is only about 
Off 5 millim. The taps (24) and (26) were then closed and tap (T) opened to allow 
the removal of the tube (t'). A little water was brought over the taps at (24) 
and (26). Vessels (9), (10), (13), (14) and (15) were then again brought to a high 
vacuum, and it is evident that the air still contained in the channels of the 
taps (24) and (26) (the pressure in them being 0T5 millim., 
and the volume about 0'02 centim.) could later on introduce, 
when opened to allow liquid to pass through them to (9) or 
(10), a contamination with air into the vessels of only about 
0 15 x 0 0w ~~~ Taps (16), (6), (17) and 
1500 
= 0'0000002 millim. 
Fig. 4. 
(11) were now closed and a concentrated solution of caustic 
potash in water, first boiled in a vacuum and freed from air, 
and kept in an evacuated flask, poured into the funnel of (24). 
Some of the caustic potash solution was forced into (9) 
through tap (24), but not so as to reach the tube leading 
from (9) to (10), to prevent the vapour pressure in (9) from 
pressing the solution into (10). Into the funnel of (24) a 
mixture of two parts of concentrated sulphuric acid and of one 
part of water boiled out in vacuo was quickly introduced. About 
250 cub. centims. of the sulphuric acid solution was rapidly 
passed into (10), and a burner placed under it ; more caustic 
potash solution was again passed into (9) until tube (32) in (9) 
was covered about 2 centims., when the vessel (10) was rapidly 
heated by passing a flame round it. In this way the caustic potash solution may be 
prevented from passing into (10) through tube connecting (9) and (10), and it 
a trace of it does pass into (10) it is subsequently neutralised by the sulphuric acid 
and does not affect the result in any way. Vessel (10) must be heated on all sides to 
avoid bumping. Tap (11) is turned off during the formation of carbon monoxide to 
prevent the distillation of water into vessels (13) and (14) containing solid caustic 
potash and phosphorus pentoxide. The carbon monoxide formed in (10) passes 
through a solution of caustic potash in (9), leaving there any traces of carbonic acid 
or of sulphurous acid, and it presses the mercury in (33) down until it begins to 
bubble through the mercury seal in (12), passing from there through tube (34) to the 
open air. The carbon monoxide is then pumped up at the end (35) till the pressure 
in (8) and (10) becomes about 150 millims.. the carbon monoxide which is still being 
formed bringing the mercury in tube (33) down again till it begins to bubble through 
the seal in (12). Repeating this several times, we expel the last traces of air from 
the vessels and liquids. The vessels (13), (14), (15), (5) and (18) were then tilled 
with carbon monoxide. Tap (11) is partially opened, so that the carbon monoxide 
should not bubble too rapidly through the solution of caustic potash and only slowly 
