A Text-book of Chemical Arithmetic

Abstract

IN the preface it is stated that this book “is designed especially for the use of students of quantitative analysis, many of whom, even after having taken extensive courses in higher mathematics, show little ability to solve simple chemical problems. Certain portions of the work are suitable also-for the use of those who are studying elementary chemistry.” It appears, therefore, that an American professor is no better off than his English cousin in this matter of student arithmetic The difficultv is two-fold. In the first place, the student has never been taught arithmetic in relation to actual measurements, but has been exercised in fictitious transactions with oranges and nuts, rods, poles or perches, and vats into which liquor flows at the rate of so many gallons a minute and out of which it flows (notwithstanding the dwindling pressure) at another exact and steady rate. The result is that the student has no idea of the relation of magnitude to measurement, and no opinion whatever on the subject of significant figures; he cannot use logarithms or a slide-rule, and is un practised in contracted methods of computation. In the second place, it is very likely that he has no sound idea of proportion. Given a student in this condition—and it is still the common case—the teaching of what is called chemical arithmetic becomes a serious part of the duties of a teacher of chemistry. The fundamental numbers of chemistry—the atomic weights—are proportional numbers, and it may be said without exaggeration that the failure to realise this and the inability to see how proportional numbers may be used for the calculation of absolute weights, locate the real pans asinorum of elementary chemistry.

A Text-book of Chemical Arithmetic.

By Horace L. Wells. Pp. vii + 166. (New York: John Wiley and Sons; London: Chapman and Hall, Ltd., 1905.) Price 5s. 6d. net.