32 PRESIDENTS ADDRESS. 
And life introduces an incalculable element. ‘The vagaries of a 
fire or a cyclone could all be predicted by Laplace’s Calculator, given 
the initial positions, velocities, and the law of acceleration of the mole- 
cules; but no mathematician could calculate the orbit of a common 
house-fly. A physicist into whose galvanometer a spider had crept 
would be liable to get phenomena of a kind quite inexplicable, until 
he discovered the supernatural, 7.c. literally superphysical, cause. I 
will risk the assertion that Life introduces something incalculable and 
purposeful amid the laws of physics; it thus distinctly supplements 
those laws, though it leaves them otherwise precisely as they were 
and obeys them all. 
We see only its effect; we do not see Life itself. Conversion of 
Inorganic into Organic is effected always by living organisms. ‘The 
conversion under those conditions certainly occurs, and the process 
may be studied. Life appears necessary to the conversion; which 
clearly takes place under the guidance of life, though in itself it is a 
physical and chemical process. Many laboratory conversions take 
place under the guidance of life, and, but for the experimenter, would 
not have occurred. 
Again, putrefaction, and fermentation, and purification of rivers, 
and disease, are not purely and solely chemical processes. Chemical 
processes they are, but they are initiated and conducted by living 
organisms. Just when medicine is becoming biological, and when the 
hope of making the tropical belt of the earth healthily habitable by 
energetic races is attracting the attention of people of power, philo- 
sophising biologists should not attempt to give their science away to 
Chemistry and Physics. Sections D and H and I and K are not really 
subservient to A and B. Biology is an independent science, and it is 
served, not dominated, by Chemistry and Physics. 
Scientific men are hostile to superstition, and rightly so, for a 
great many popular superstitions are both annoying and contemptible ; 
yet occasionally the term may be wrongly applied to practices of which 
the theory is unknown. To a superficial observer some of the practices 
of biologists themselves must appear grossly superstitious. To combat 
malaria Sir Ronald Ross does not indeed erect an altar; no, he oils a 
pond,—making libation to its presiding genii. What can be more 
ludicrous than the curious and evidently savage ritual, insisted on by 
United States Officers, at that hygienically splendid achievement the 
Panama Canal,—the ritual of punching a hole in every discarded tin, 
with the object of keeping off disease! What more absurd, again— 
in superficial appearance—than the practice of burning or poisoning 
a soil to make it extra fertile! 
Biologists in their proper field are splendid, and their work arouses 
keen interest and enthusiasm in all whom they guide into their domain. 
