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For the help of students who may use this book at the commencement of their chemical studies, and especially for those who may not be working under the immediate guidance of a teacher, the following hints are given :

Begin by carefully reading the first four chapters (pages 1-24). Then pass on to Part II. (page 171), and begin the study of the four typical elements, hydrogen, oxygen, nitrogen, and carbon, and their compounds, in the order in which they are treated. Accompany your reading by performing as many of the experiments referred to as possible, in order that you may become practically familiar with the substances you are studying.

During the time occupied in the study of these four elements and their compounds, again read Chapters I. to IV., and slowly and carefully continue reading Part I., so that by the time Part III. is reached, you may have fairly mastered at least the first thirteen chapters of the Introductory Outlines.

The order in which the elements are treated in Part III. is based upon the periodic classification, therefore read the short introductory remarks at the commencement of the various chapters, in the light of the table on page 117.

Throughout the book temperatures are given in degrees of the Centigrade thermometer. 1° Centigrade equals 1.8° Fahrenheit, and as the zero of the latter scale is 32° below that of the Centigrade, temperatures given in degrees of one scale are readily translated into degrees of the other, by the simple formula

(n°С. x 1.8) + 32 = °F. The abbreviation mm. stands for millimetre; the 1000 part of a metre (1 metre = 39.37079 inches; or roughly, 25 mm. = 1 inch). The abbrevation c.c. signifies cubic centimetre; the tooo part of a cubic decimetre, or litre (I litre = 1.76077 pints).

I gramme (the weight of 1 c.c. of distilled water, taken at its point of maximum density)= 15.43235 English grains.

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