106 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
and Lessons of Recent Biological Research,” in considering 
how advance of knowledge has promoted the general welfare 
of mankind, comes to the conclusion that “during the past 
one hundred years it is biological science that has contributed 
most to the well-being of humanity.” This is the thesis which 
he develops in detail with many illustrative examples showing 
the application of purely scientific biological investigations 
in the laboratory to agriculture and allied industries, protection 
from animal pests, public health, preventive medicine, sanita- 
tion and bacteriology, the increase, improvement and 
preservation of food matters, and their protection from 
infection. ‘‘ All these activities have been completely dependent 
on applied biology for their methods and processes, and have 
changed and developed rapidly with the progress of that 
science. Taken together they constitute an immense con- 
tribution to human welfare, present and future.” 
Finally, Dr. Eliot makes an important poimt in his 
statement that “the long series of successful applications 
of biological science illustrates strikingly the impossibility of 
drawing any fixed line of demarcation between pure and 
applied science, or of establishing an invariable precedence 
for one over the other. Sometimes an application is suddenly 
made of one fragment of an accumulation of knowledge which 
men of science have made without thought of any application, 
and sometimes a bit of knowledge successfully applied 
stimulates purely scientific workers to enter and ransack 
the field from which the bit came . . No mortal can 
tell how soon a practical application of a scientific truth, 
which seems pure in the sense that it has no present application, 
may be discovered; and on the other hand innumerable 
applications are nowadays made of truths which five years 
or fifty years ago seemed as remote from all human interests 
as the observation attributed to Thales, that a bit of amber 
tubbed with a piece of silk would repel pith balls suspended 
