ANNUAL ADDRESS OF THE PRESIDENT. XLVII 
of nature by the racks and thumbscrews of physical enquiry. In- 
stead of taking our atoms as they were distilled and attenuated by 
the refining brains of an Anaxagoras, a Democritus, an Epicurus, 
or a Leibnitz, we can now take them as weighed and measured by 
the quantitative, qualitative, or volumetric analysis of modern 
chemistry, in ways that Anaxagoras or Democritus or Epicurus 
or Leibnitz never dreamed of in their philosophy. The distance 
between the 5th century before Christ and the year 1800 is meas- 
ured as well by John Dalton as by John Howard. John Dalton 
and John Howard would have each been impossible in the days 
of Democritus—the one as much so as the other. John Howard 
plunged into the reek of European prisons at the impulse of a 
Christian philanthropy unknown to the Greek, with all his love of 
the Good, the Beautiful, and the True. John Dalton plunged into 
the reek of the Lancashire marshes,” at the impulse of an abstract 
science unknown to the Greek with all his love of dialectics, of art, 
and of xsthetic culture. John Howard, to use the fine phrase of 
Burke, taught men who love mercy to “ take the gauge and dimen- 
sion” of human misery. John Dalton taught men who love truth 
in disinterested studies to take the gauge and dimension of the ele- 
ments which compose the physical Universe. Who was this John 
Dalton that stands in such typical relation with the scientific 
thought of our century? 
Given, a man “meditative and ratiocinative;” a meteorologist, 
curious in all eudiometrical research, and, therefore, perpetually 
experimenting on the constitution of mixed gases; a teacher of 
arithmetic, so given to mental numeration that on his first visit to 
London he counts all the carriages he sees while wending his way 
to the Friends’ Meeting House on a Sunday; a chemist, who took 
the diffusion and absorption of elastic fluids as his special province 
of investigation; a theorist, who never theorized without an exper- 
iment, and an experimenter who never experimented without a 
theory, and you have John Dalton, the father and founder = the 
Modern Atomic Philosophy. 
As early as the year 1802, in some experimental combinations of 
oxygen with nitrous gas, Dalton discovered that “the elements of 
oxygen combined with a certain portion of nitrous gas, or with 
twice that portion, but with no intermediate quantity.” Though he 
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* He obtained his inflammable gas from these marshes. 
