336 Remarks on Chemical Theory, and oi 
memorandum, printed in connexion with the article fluoric 
acid or better perhaps ina general appendix, consi’ sim- 
ilar things. ‘The same is probably the fact with s 
principles, both elementary and proximate, and ae soon 
we imagine, conduce to the progress of the science, and to 
the comfort and advancement of learners, if newly discov- 
ered things, when their character is dubious, were kept long- 
er in waiting at the door, until their title to admission and 
proper were very clearly made out. In chemis- 
try, as in other branches of knowledge, we are too apt to 
upon the presumption, that we know. every thing, 
and we construct our arrangements accordingly ; but, our 
errors it is probable, are not few, and our deficiencies, must 
without doubt, be very numerous. 'The unexpected dis- 
covery of some new and important principle, frequently 
uces a very extensive influence on the relations of other 
bodies, and of course on the state of the science. How 
great was the change produced by the discovery of oxigen, 
and of the constitution « of water, and nd of pagent maapliens, 
new views of chlorine introduced into almost st every. par 
of the science of chemistry. The subject of chlorine 
one respecting which, we may perhaps differ from most of 
whose opinions we respect. 
In the first place, we are far from thinking that it is expe- 
dient, to introduce this difficult and complicated subject, in- 
to the early part of a course of lectures or of a treatise. It 
is ossibl ; i e theory, to examine, 
= 
Por tae sh q ee eee hich ee 
rine acts a party without an acquaintance with a 1 large number 
phenomena 2 and reasoning. We are aware ei if i it be, as 
rth ihe nore we have gone on so far in 
eee. 
* 
