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chemical forces acting through the lungs, stomach and 
general circulations are alike inexplicable, upon any theory 
however ingenious, of slow combustion, or of machine 
power. 
Although the term vital force may be somewhat vague, 
it seems to point out the special energies, that originate 
organic forms, and to multiply and expand them by a series 
of spontaneous actions, from the seeds and ova, to build up 
the living structures of plants and animals, and upon the 
attainment of their maturity, the subsidence of those 
energies commences, nor can any intrinsic aid, or stimuli 
prevent their extinction at the appointed time. 
If the term force be made to include those exerted by the 
vital organs, and if the conservation of such forces be a 
practical reality, then the living energies need never to 
“ fade away and expire/’ except through the wilful neglect 
of the conservative doctors. 
I will here add, in the words of a profound thinker, that, 
in organic life, “every train of development exhibits in its 
course an adherence to plan, which can only have its ground 
in an internal vital destination. It exhibits at the same 
time an independence of all external influences, which testi- 
fies to the internally given force of vitality.”* 
It must be observed that these comments on vital forces 
relate solely to those functional energies that produce physi- 
cal action, and which are quite apart from the “ moral and 
intellectual forces” exerted externally by sentient beings 
upon each other — a subject of wider and far higher nature 
than any of mere physical action. 
I venture to recommend a careful perusal of the learned 
and eloquent essay (in Once a Week) before quoted, in order 
to a clear and full comprehension of what is called “ the 
great philosophical doctrine of the present era of science.” 
All know that in the act of breathing, the carbon in the 
# Bay Society’s Bot. and Phys. Memoirs, 1863. 
