PREFACE TO THE FIRST EDITION.

AN extensive experience in preparing medical students for examination in Chemistry has satisfied the writer that the incomplete knowledge of this department of medical science, so often exhibited by students and physicians, is generally due to their inability to study the subject thoroughly without encroaching in too great a degree on the time required for the more practical branches of their profession.

Most students appear to be justified in claiming that they have derived much profit from the systematic course of "quizzing" which is in vogue at the medical schools This benefit is attributable, no doubt, to the fact that by this mode of instruction essential points are brought out in the form of questions which exact attentive consideration before adequate answers to them can be given.

In the volume here presented the author has the same object in view, and while he trusts that it will not be the means of dispensing with the deeper study of the subject, he feels assured that unless the frame-work of knowledge be first well constructed, substantial progress will be quite impossible.

If this little work shall tend to give students a better understanding of Chemistry, and with it a greater love, or perhaps less of a distaste, for the pursuit in connection with their medical studies, the writer considers that he will have achieved much of that which he attempted.

As an introductory course to Chemistry in most, if not in all, medical colleges includes the principles of Physics, some essential questions on this subject precede the chemical part of the work. Theoretical Chemistry, though treated in a separate chapter, is also frequently referred to throughout the text. The classification of the elements is somewhat at variance with the most modern ideas of pure Chemistry, but it has been given with the view of presenting the matter in logical sequence to the medical mind. Toxicology has received ample consideration under the head of each element or compound which possesses markedly poisonous properties. Analytical processes have been brought out as far as compatible with the condensation of so large a subject within so limited a space. No separate chapter or part is devoted to the "urine and its analysis," its components being considered in the order of their precedence in the adopted arrangement.

The questions and answers of this Manual have been so arranged as to conform to the principal text-books on the subject. For this purpose the authoritative works of Fownes, Attfield, Richter, Charles, Barker, and Witthaus, as well as Holland on the Urine, and Draper and Ganot on Physics, have been freely used in its preparation.

PHILADELPHIA, PA., 333 South Twelfth St.
August, 1888.

L. W.