376 Dr. F. F. Blackman and Mr. A. M. Smith. [Dec. 19, 
importance in this method of investigation; the rate aimed at was about 
300 c.c. per hour. The actual rate was continually determined by measuring 
J] LSS 
3 nal size 
Section 
of Valve Y 
Front of Bath showing Window and Chamber. 
the amount overflowing from the pipettes into the graduated cylinders 
F and G. Any significant departure from uniformity was corrected by 
Bigs ls 
a 
