PREFACE. 



There are quite a number of books on botany, many of which serve 

 a very excellent purpose. For the most part, however, they are not adapted 

 for the use of students in the applied sciences where the knowledge of 

 botany is to be utilized later in practical work. It is now more than sixty 

 years since Schleiden showed the value of the microscope in the examina- 

 tion of drugs and Schacht demonstrated its usefulness in the study of 

 textile fibers. Since that time quite a number of works have been pub- 

 lished dealing with the microscopy of special technical products, as drugs, 

 foods, fibers, woods, etc., but there have been no text-books which could 

 be employed in the courses on applied and economic botany that would 

 satisfy either the desires of the student or fit the graduate for practical work 

 in commercial life. It is not generally appreciated that there is a depart- 

 ment of applied botany which is distinct from every other phase of botani- 

 cal study ; the point of view and the technique being peculiarly its own and 

 the problems so intricate and important that they should ever be held be- 

 fore the student and command his constant attention. It is almost self- 

 evident that courses in botany which are intended for intellectual culture 

 or scientific discipline are not adapted for technical courses of instruction. 

 In the latter the student has a right to ask for the application of the in- 

 struction which he is receiving and to show an interest in proportion as the 

 instructor is able to demonstrate its value. There are some who consider 

 that a more or less superficial knowledge of botanical principles and micro- 

 scopic technique is sufficient for the student in applied or economic botany. 

 On the contrary, we find that a rather extended knowledge of botany and 

 a very thorough preparation in certain phases of botanical work are 

 absolutely required in order to prepare him to meet and solve the many 

 problems that arise in the commercial world. Many of the commercial 

 problems that are held to be chemical and which are handed to the chem- 

 ist for solution are, as a matter of fact, of a botanical character and can 

 be solved with less expense and less time by the trained botanist. What 

 is really needed is the trained analyst, who, while proficient with chemical 

 methods, is also thoroughly versed in microscopic technique. We have 

 come to a time, if real progress is to be made both in the manufacture of 

 plant materials and in the examination of commercial substances, that it 

 is necessary to bring both chemical and botanical training and knowledge 

 to bear upon the problems involved. 



Nearly all of the problems upon which one is liable to be consulted in 

 active practice, whether they involve new processes of manufacture or 

 the examination of the finished market material, show at the outset that 

 the analyst must have a very thorough knowledge of the cell constituents 

 and the tissues composing the raw material. It is for this reason that 

 almost one-half of the material of this volume is devoted to the study of 



V 



