Introduction to the Preparation of Organic Compounds

to have it printed. The considerations which have governed the selection and arrangement of the are for the most part of a practical nature, such as the cost of the materials and apparatus, and the easiness, shortness, and freedom from danger of the operations themselves. The prescriptions are often tested, and are such that the student can make all the preparations in one Semester at a cost of about forty shillings for materials. Examples are included of almost all operations, and of the commonest synthetic methods. Theoretical explanations are avoided as far as possible, because it is more stimulating for the students to obtain information on the strength of their own observations by consulting the original literature or the text-books, or by verbal instruction. In working out and practically testing the directions, I have had the assistance of Dr Wilhelm Wislicenus, to whom my thanks are due. EMIL FISCHER - PREFACE TO THE SEVENTH EDITION - IN comparison with the sixth edition, the number of preparations has had to be increased by one-half in order to include some new reactions, and in order to be able to give attention to the field of research chiefly worked upon in the organic department of this laboratory. d As, however, the course thereby became so , extensive that most students were no longer able to complete it in three or four months, I have divided it into two parts. The first contains the exercises required of chemists. With the exception of those marked in index and contents-list with n star, they are here compulsory, i. e. they must be carried out before the usual piece of research is commenced. The second part is intended chiefly for medical an d biologists who wish to acquaint themselves with the methods of organic chemistry. For previous practice they usually carry out preparations in the first part, and they usually require for both lots not more than one Semester. In order to prevent accidents, the students in this laboratory are made aware of the dangers of chemical work by means of detailed notices, and it seemed to me advisable to place these warnings at the beginning of this book. There - is, in addition, at the end a small table giving the strengths of the most common solutions, the concentrations of which are chosen to be simple multiples of the normal strength. Their use has proved very convenient owing to the simplification of calculations which it effects. In the rewriting of the book, which has also been extended to the older preparations and takes into account the practical experience of the last five years, I have been ably assisted by Professors and Doctors R. Pschorr, 0. Em rnerlirlg, 0. Diels, E. Abderhalden, F. Sachs, H. Leuchs, E. Kiinigs, and R. Kempf, and I wish to offer them my hearty thanks. To Professor Diels I am also indebted for the skilful preparatio l of the drawings. EAIIL FISCHER. F . L I . I IF , .. lprz 1905... --This text refers to the Paperback edition.