434 
ON CHEMISTRY. 
and chemists, in their researches, have followed the old beaten track ; 
they have been almost wholly led by the influence of authority ; they 
have taken things for granted, upon the bare ipse dixit of some great 
precursor: in a word, they have failed to investigate or reflect for 
themselves. The consequences have been, that little or no advance 
has been made in physiological science ; and those who sought the 
solution of phenomena, have been content to ascribe the effects they 
witnessed, to causes having no foundation in natural fact. It will be 
my chief object, as I proceed, to demonstrate, that the foregoing state¬ 
ments arc not mere assertions. I respect authority, and would not 
undervalue it; the labours of a Lavoisier, a Priestley, a Du Hamel, 
a Davy, and a multitude of other philosophers, deserve to be held in 
high estimation, for truly, “their works do follow them but I con¬ 
tend that Science is retarded by that reverential deference, which 
seems to yield implicit faith to the opinions of great men. The very 
differences that are constantly found to exist, prove, to a demonstra¬ 
tion, that errors must, to an equal extent, abound. Some of these 
errors I shall endeavour to point out; and in order to do so, as well 
as to guard the reader against the prevalence of those mistaken no¬ 
tions heretofore regarded as facts, I shall introduce the subject of 
these papers by an elucidation of several of the leading Chemical 
and Physiological Terms that must, of necessity, be repeatedly em¬ 
ployed ; occasionally giving a plain and simple account of the source 
or derivation of the terms, in order to familiarize the reader with the 
origin of the science he studies; for I am convinced, that nothing 
tends so effectually to impress the memory, as a clear and precise 
knowledge of the meaning of whatever it undertakes to grapple with. 
The adjective word Chemical is clearly derived from Chemistry, 
formerly, and perhaps more correctly, spelt CAymistry; because it 
was derived, either from the Greek word x v H- 0 ^ (Chumos) which 
literally means juice, and from which the word Chyme has been ob¬ 
tained ; or from x v l Ma ( chumia ) which may be explained as the act 
of melting, or operating by heat upon solids or fluids. Hence, the 
art of chemistry includes every operation of combination, separation, 
liquefaction, sublimation or diffusion, by the agency of heat or fire. 
There is, however, some perplexity or confusion in the origin of the 
word ; and therefore the reader may be referred to the following ex¬ 
tract from Johnson's quarto Dictionary : “ Chymistry, sub. fern, de¬ 
rived by some from yjj^oc, juice, or x vo ° 1° melt; by others, from 
an Oriental word, kema, black. According to the etymology, it is 
written with y or e. Chemistry, viewed in the modern acceptation 
of the term, that is, as the agent of analyzing or combining material 
