tical conceptions too long,
for the atomic theory is a great aid in making rapid progress in the
study of chemistry. At least two or three weeks are well spent in
studying fundamental chemical reactions as facts quite independent of
any theories whatsoever, in order that the student may thoroughly
appreciate the nature of chemical change and become familiar with
enough characteristic and typical cases of chemical action so that the
general laws of chemical combination by weight and by volume may be
logically deduced and the atomic and molecular theories presented as
based upon those laws.

Up to this stage the reactions should be written out in words and all
formulation should be avoided, so that the student will not get the
idea that "chemistry is the science of signs and symbols," or that
"chemistry is a hypothetical science," but that he will feel that
chemistry deals with certain very definite, characteristic, and
fundamental changes of matter in which new substances are formed, and
that these processes always go on in accordance with fixed and
invariable laws, though they are influenced by conditions of
temperature, pressure, light, electricity, and the presence of other
substances in larger or smaller amounts. The theory and formulation
when properly introduced should be an aid to the student, leading him
to see that the expression of chemical facts is simplified thereby.
Thus he will never make the error of regarding the symbol as the
fundamental thing, but he will from the very outset look upon it
simply as a useful form of shorthand expression, as it were, which is
also a great aid in chemical thinking. Facts and theories should ever
be kept distinct and separate in the student's mind, if he is to make
real progress in the science.

A thoroughgoing, logical presentation of the subject, leading the
student slowly and with a sense of perfect comprehension into the
deeper and more difficult phases, should constitute one of the prime
features of the work of the first year. Interest should constantly be
stimulated by references to the historical development of the subject,
to the practical applications in the arts and industries, to
sanitation and the treatment of disease, to the providing of proper
food, clothing, fuel, and shelter, to the problems of transportation
and communication, to the chemical changes that are constantly going
on in the atmosphere, the waters, and the crust of the earth as well
as in all