A text-book of elementary chemistry / by Alexander Smith.

  • Alexander Smith
Date:
1915
Catalogue details

Licence: In copyright

Credit: A text-book of elementary chemistry / by Alexander Smith. Source: Wellcome Collection.

    15/492 page 7
    Vll The second variety of questions may involve reasoning from, and reflection upon, the facts and principles, and may not be wholly answerable by mere quotation from the text.* Such questions will powerfully stimulate the interest in the science felt by the more alert or more mature pupils. They may awaken little response from the duller or more indifferent, however, and must be used with good judgment. The exer- cises at the end of each chapter contain suggestions for questions, mainly of the second kind. It is assumed that the teacher will himself prefer to prepare all the simpler, systematic questions on the assigned lessons and thus give effect to his own prefer- ences in respect to selection and emphasis. In Chapters XXXII and XLII an opportunity for syste- matic review of the non-metals and of the metals, respectively, is afforded. Since it takes the form of a plan for recognizing unknown substances, the point of view is new to the pupil and even the appearance of repetition is avoided. Yet a rigorous review of a large number of facts is secured. At the same time the process invites to activity the mental traits that so suc- cessfully rivet the attention of young people upon a detective story or a guessing competition. They forget that they are learning. In performing the laboratory work connected with these chapters, the pupil makes use of the experiments pre- viously performed, and suddenly realizes as never before some of the possibilities in the way of practical application which are characteristic of the science. An attempt has been made to arrange the matter on peda- gogical principles, though without too much distortion of the conventional order. Thus, when ozone, hydrogen peroxide, and hypochlorous acid are placed with oxygen, water, and chlorine, respectively (as they would be in a work of reference), their characteristic reactions are either omitted, or, if intro- * Chap. I, exercise 2. Chap. II, exercises 1, 3, 4, 5, 6, 7. Chap. Ill,
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