Chlamydomonas and other vegetable cells. 
185 
3. Variation of the death-rate with the Concentration of the Poison. 
To small quantities of a culture of very numerous actively-moving cells 
of Chlamydomonas about 1 cc. of Resorcin solutions of different strengths 
log. c . 
Fig. 2. Diagram showing direct proportion between logarithm of concentration of poison 
and logarithm of time for poisoning to reach completion. 
were added and the times recorded for all, except 3-5 cells, to cease moving 
under the field of the microscope. The concentrations of the poison and 
the times required for cessation of movement are given in the first two 
columns of Table III, and in the third column the average times required 
for movement to cease. 
On plotting the logarithms of the times and of the concentrations the 
points are seen to lie upon a straight line ; that is, the logarithms show 
a direct proportion. In the case of the point corresponding to the least 
concentration, the discrepancy is accounted for by the difficulty in determin- 
ing the exact time-value, as may be seen from the varying values given in 
the table. 
Since the logarithms of time (t) and of concentration (c) are directly 
proportional 
log t + k log c — a constant. 
This is found to be the case, taking k — 1-21, as shown by the constant 
values in the last column. 
In a chemical reaction where one molecule of one compound reacts with 
k molecules of another compound which is in great excess, this equation is 
