differences in spelling and punctuation in the different chapters (e.g. cocoanut in one chapter and coconut in another). These differences were left in the text as they appeared. For Text: A word surrounded by a tilde such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like _this_ signifies the word is italics in the text. For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers in equations denote a subscript. The Degree symbol has been changed to deg. in the ASCII file. Minor typos have been corrected and footnotes moved to the end of the chapters. * * * * * PREFATORY NOTE. The material contained in this work appeared several years ago in serial form in the American Perfumer and Essential Oil Review. Owing to the numerous requests received, it has been decided to now place before those interested, these articles in book form. While it is true that the works pertaining to the soapmaking industry are reasonably plentiful, books are quite rare, however, which, in a brief volume, will clearly outline the processes employed together with the necessary methods of analyses from a purely practical standpoint. In the work presented the author has attempted to briefly, clearly, and fully explain the manufacture of soap in such language that it might be understood by all those interested in this industry. In many cases the smaller plants find it necessary to dispense with the services of a chemist, so that it is necessary for the soapmaker to make his own tests. The tests outlined, therefore, are given as simple as possible to meet this condition. The formulae submitted are authentic, and in many cases are now being used in soapmaking. In taking up the industry for survey it has been thought desirable to first mention and describe the raw materials used; second, to outline the processes of manufacture; third, to classify the methods and illustrate by formulae the composition of various soaps together with their mode of manufacture; fourth, to enumerate the various methods of glycerine recovery, including the processes of saponification, and, fifth, to give the most important analytical methods which are of value to control the process of manufacture and to determine the purity and fitness of the raw material entering into it. It is not the intention of the author to go into great detail in this work, nor to outline to any great extent the theoretical side of the subject, but rather to make the work as brief as possible, keeping the practical side of the subject before him and not going into concise descriptions of machinery as is very usual in works on this subject. Illustrations are merely added to show typical kinds of machinery used. The author wishes to take this opportunity of thanking Messrs. L. S. Levy and E. W. Drew for the reading of proof, and Mr. C. W. Aiken of the Houchin-Aiken Co., for his aid in making the illustrations a success, as well as others who have contributed in the compiling of the formulae for various soaps. He trusts that this work may prove of value to those engaged in soap manufacture. E. G. T. January, 1922 TABLE OF CONTENTS. CHAPTER I. Page. RAW MATERIALS USED IN SOAP MAKING 1-30 1. Soap Defined 1 2. Oils and Fats 1-2 3. Saponification Defined 2-3 4. Fats and Oils Used in Soap Manufacture 3-4 Fullers' Earth Process for Bleaching Tallow 4-6 Method for Further Improvement of Color in Tallow 6 Vegetable Oils 6-9 Chrome Bleaching of Palm Oil 9-12...