COOLEY’S CYCLOPÆDIA
OF
PRACTICAL RECEIPTS
AND
COLLATERAL INFORMATION

PREFACE TO THE SIXTH EDITION

Some one has said that “when a book reaches a fifth edition it scarcely requires a preface.” If such be true of a fifth, it is probably still truer of a sixth edition, and therefore this issue of ‘Cooley’s Cyclopædia’ might fairly be sent forth to the public without any prefatory remarks whatever. It is, however, desirable to point out that the present edition is larger than the last by about six hundred pages; that much greater space than hitherto is devoted to Hygiène (including sanitation, the composition and adulteration of foods) as well as to the Arts, Pharmacy, Manufacturing Chemistry, and other subjects of importance to those for whom the work is intended.

The articles on what is commonly termed ‘Household Medicine’ have been amplified and numerically increased.

Short accounts of the more common diseases, their causes, symptoms, and treatment, affecting the domesticated animals have been introduced. “Here, however, it may be useful to repeat the cautions given in other parts of this volume, as to the impropriety of unnecessarily meddling with the healing art or neglecting a prompt application” (where and when possible) “to a duly qualified practitioner in all cases demanding medical or surgical aid.” These remarks of Mr Cooley are as applicable to cases of Veterinary as to those of Human Medicine.

Numerous authors have necessarily been consulted; a list of them, and the titles of their works from which information has been derived, will be found at the end of the second volume. When extracts have been introduced verbatim the authority is quoted in the body of the book.

Many of my scientific confrères have rendered me valuable aid in preparing this edition; but I am particularly indebted to my accomplished and zealous friend Mr John Gardner for his hearty and constant co-operation; to Dr Lionel Beale for his kindness in revising the articles on “Urine,” “Urinary Diseases,” &c., as well as for the

use of cuts from his celebrated works on these subjects; to my friend and former pupil Mr F. Woodland Toms for revising and rewriting the articles on “Sewage” and “Water;” and to my assistants Mr James Bayne and Mr Cuthbert Neison for correcting “proof.”

The laborious task of preparing a sixth edition of ‘Cooley’ having been accomplished, it is hoped that, due consideration being given to the magnitude of the work and to the great variety of the subjects treated, it will be found to be practically free from important errors, and that it will meet with, at least, the same gratifying reception as that accorded to its predecessors.

PREFACE

The design of the present work is briefly, but not completely expressed in its title-page. Independently of a reliable and comprehensive collection of formulæ and processes in nearly all the industrial and useful arts, it contains a description of the leading properties and applications of the substances referred to, together with ample directions, hints, data, and allied information, calculated to facilitate the development of the practical value of the book in the shop, the laboratory, the factory, and the household. Notices of the substances embraced in the Materia Medica of our national pharmacopœias, in addition to the whole of their preparations, and numerous other animal and vegetable substances employed in medicine, as well as most of those used for food, clothing, and fuel, with their economic applications, have been included in the work. The synonymes and references are other additions which will prove invaluable to the reader. Lastly, there have been appended to all the principal articles referred to brief, but clear, directions for determining their purity and commercial value, and for detecting their presence and proportions in compounds.

The sources from which I have derived the vast mass of materials forming this volume are such as to render it deserving the utmost confidence. I have invariably resorted to the best and latest authorities, and have consulted almost innumerable volumes, both British and foreign, during its compilation. Secondary channels of information have been scarcely ever relied on when original authorities were within my reach. A large portion of the work has been derived from my personal experience and observations in the departments of applied chemistry and hygiene, and from the processes of various laboratories and manufactories, many of which I can the more confidently recommend from having either inspected or witnessed their employment on an extensive scale. The indiscriminate adoption of matter, without examination, has been uniformly avoided, and in no instance has any formula or process been admitted into this work, unless it rested on some well-known fact of science, had been sanctioned by usage, or come recommended by some respectable authority. The settlement of doubtful or disputed points

has often occupied me a greater number of hours, and not unfrequently a greater number of days, than that of the lines of letter-press which convey the results to the public. In all cases precedence has been given to the standard formulæ of our national pharmacopœias, and to those processes which long experience, or well-conducted experiments, have shown to be the most successful, profitable, and trustworthy. In general, the sources of information have been indicated, for the purpose of enabling the reader to form a better estimation of their value. Whenever this is not the case, in reference to borrowed formulæ and data, the omission has arisen from the impossibility of determining to whom the merit is justly due.

I have endeavoured as much as possible, in the present work, to avoid confusion of the medical weights with those commonly used in trade and commerce—an attempt which, so far as I am aware, has not been successfully carried out in any other quarter. For this purpose I determined to entirely abandon the usual arbitrary signs or characters employed to represent the divisions of the apothecaries’ pound, and to distinguish the two weights from each other, by simply printing, in different type, the plain English names and