ÆäÀÌÁö À̹ÌÁö
PDF
ePub

PREFACE TO THE SECOND EDITION.

THE following pages are an instalment of the Second Edition of the Author's "Manual of Practical Chemistry"-the First Part of the New Edition being now issued separately under the title of "Foods: their Composition and Analysis," and the Second Part under that of " Poisons: their Effects and Detection." The reasons for the alteration of the title are sufficiently obvious: the present appellation is distinctive, rendering impossible any confusion between this Manual and others (of a widely different scope and manner of treatment) which might come equally under the designation, "Practical Chemistry."

The present Volume, however, is not a mere reprint of the Division, "Foods," in the First Edition. It has been thoroughly revised and re-written, where necessary, and enlarged by the addition of new matter to more than double the number of pages allotted to the subject in the original work.

The Historical Introduction prefixed is the result of considerable labour and research, and, it is hoped, will be found— together with the review of English Legislation, Past and Present, relative to Adulteration-not without interest. As in the First Edition, abstracts of a few legal cases are given at the end of the chief Articles. These have been carefully selected, as illustrative either of ingenious defence, or of certain points in the Adulteration Acts. It has often been remarked that private individuals rarely avail themselves of the "Sale of Food and Drugs" Act. This, probably, is due to insufficient acquaintance with the technical details of the mode of procedure, and the Author has, therefore, been careful to explain the "Purchase" sections fully in their relations both to the official Inspector and to the private purchaser. In the Appendix will be found the Text, entire, of the English laws at present in

operation, as well as the best and most recent of the American Acts relating to the Adulteration of Food.

In the Scientific Portion of the work, the professional Chemist will find details of most of the processes of any value in Food Analysis hitherto published, and in all cases (either by the aid of Footnotes, or in the Bibliography appended to each Article) the original source of the information is indicated. In addition, are given a large number of Processes, either invented or improved by the Author, and not previously published—such, e.g., as those described in the Articles on Milk, Butter, Tea, Flour, Water, &c.

Numerous Tables, some of which are indispensable and others convenient, have also been added; and new Illustrations, from original drawings, introduced.

The Article on Milk-a special feature of the First Editionis still further enlarged, and contains the Author's most recent researches on the subject. It may, perhaps, be considered a fairly complete Monograph. In the Article on Water (added by request) the application of an improved process for combustion in a vacuum is detailed, and the importance of Biological methods of examination is insisted upon-not as supplementary to Chemical tests, but as of equal (if not of superior) value to these.

Though the scope of the Manual is mainly that of a Laboratory Handbook, yet the dietetic and medical aspects of the more important Foods are, where necessary, fully considered, and the Author believes that a great proportion of the work is thus of that general interest which will render it useful to those who, without much chemical knowledge, yet desire to have, in a form admitting of easy reference, the latest information relative to Foods and Beverages.

In conclusion, he can only express a hope that the work, in its new shape, will be found widely useful, and more worthy of the very kind reception accorded to the First Edition.

COURT HOUSE, ST. MARYLEBONE,

April, 1882.

[merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small]
[blocks in formation]
[blocks in formation]

Antony Van Leeuwenhoek, Dr. Hy. Power, Ehrenberg, Donné,

31. General Advance of Chemistry: Neumann Caspar, Boerhaave,

34-37

[subsumed][subsumed][subsumed][ocr errors]
[ocr errors]

47

[ocr errors][ocr errors]
[subsumed][merged small][merged small][ocr errors][subsumed][subsumed][subsumed]
[ocr errors]
[ocr errors]

59, 60

62-64

[merged small][ocr errors]
[ocr errors][subsumed][merged small][merged small]

54. The best Form of Microscope-Manipulation of Tissues, .

72-74

[ocr errors]
« ÀÌÀü°è¼Ó »