388 On Vegetable Assinulation and Respiration. 
which the strength of the solution fell off again. During the middle period 
the working is all that could be desired. The effluent and affluent analyses 
are practically identical all the time, which shows that there is no loss 
of CO, during the long journey of the water current, and that the general 
procedure is satisfactory. 
Irregularities of current rate do not come into play in this form of 
experiment, and we reckon that the errors of a real experiment are bigger 
than this blank indicates, and may amount to perhaps 1 per cent., which is 
satisfactory enough. 
The divergence of the effluent and affluent values at the two ends of the 
diagram as here represented is illusory, because it is merely due to the lag 
in the effluent on account of the hour or more it takes to flow through the 
chamber and apparatus. If the values of the affluent were all moved on an 
hour in the diagram they would coincide with those for the effluent right 
through the whole experiment. This blank experiment has been chosen 
because it illustrates the lag so well, which varies in different experiments 
from 40 to 80 minutes. 
It must be borne in mind that it is not proposed to obtain critical values 
when the concentration of the CO, is rising or falling. Only when the 
series of analytical values of the affluent is nearly constant is the experiment 
considered a trustworthy one. 
In conclusion we should mention that the cost of the important parts of 
the apparatus was provided by a Government grant from the Royal Society. 
