ON CHEMISTRY. 
435 
substances, cannot be correctly applied to any body or substance 
endowed with the vital principle. Thus Avbuthnot most justly ob¬ 
serves : “ Operations of Chymislry fall short of vital force; no 
chymist can make milk or blood of grass.” I wish the reader, there¬ 
fore, most distinctly to understand, that whenever the words chemical 
or chemistry are employed, with reference to living subjects, it is 
only in conformity with custom; since the idea is wholly disclaimed 
that any process, at all identical with the operations of man upon 
dead or effete matter, is ever, in any instance, carried on in the 
vegetable or animal organized frame, so long as that frame is actuated 
by, or endowed with, the powers of life. On this head, my ideas 
will be more particularly explained in an article upon the agency of 
light. 
Physiology , physiological, are words derived from the Greek ; they 
are highly appropriate and expressive, tyvaig (phusis) by convert¬ 
ing the Greek v or u into our y, as is usually done, becomes physis, 
nature, and Xoyog [logos) is a speech, discourse, or treatise. These 
two Greek words united, form the English word, physiology, which 
means, literally, a treatise or discourse of, or concerning nature : 
hence this word, and Natural Philosophy, convey one and the same 
meaning; viz., the science or study of nature in general. Another 
word frequently employed, and more strictly applicable to the science 
of horticulture, is “ phylology,” derived from the two Greek nouns, 
Qvtov (phut on or phyton) a plant, and Xoyog (logos) before ex¬ 
plained. Vegetable physiology, and phytology, are therefore nearly 
synonymous, and express the science or study of the nature of plants. 
Having thus endeavoured to familiarize these introductory terms, 
I shall not here intrude upon your readers’ time, by an enquiry into 
the etymology and meaning of every chemical word that may occur, 
but confine myself at present to three or four, which, on all occasions, 
are made use of by those who write or speak of the components of 
vegetable or animal structure. These terms are oxygen, hydrogen, 
carbon, and we may add, azot or nitrogen. 
The word oxygen had its origin in the famous Lavoisier, who 
flourished just before the period of the first French revolution, and 
fell a victim to the blind fury of the revolutionary tribunal of Paris, 
on the 8th of May, 1794. Having been one of the farmers-general, 
he was condemned on the charge of being a conspirator, and of having 
adulterated the tobacco with water, and with ingredients obnoxious 
to the health of the citizens. 
Lavoisier thus expresses himself with regard to the origin of the 
word oxvgen : “We have given to the base of the respirable portion 
F f 3 
