PREFACE TO THE FOURTH EDITION 



The Ninth Revision of the United States Pharmacopoeia, as in no 

 previous edition, makes it important, and even necessary, that all works 

 of a pharmaceutical character be revised. 



The last revision of the Pharmacopoeia has required, on the part of 

 the revisers, very exceptional work directed toward the subject of stand- 

 ards; and inasmuch as the United States Pharmacopoeia, as well as the 

 National Formulary, is mentioned in the statute, known as the Food 

 and Drugs Law, this revision has become of greatest importance. 



Recognizing this, great pains have been taken in the revision of the 

 present edition, that the standards, whenever mentioned, shall conform 

 to the legal standard above referred to. 



Many changes have been made necessary by the fact that the U.S.P. 

 IX has deleted fifty-three vegetable drugs and has added, or raised to 

 official recognition, but four of well known drugs. 



Among the conspicuous changes in U.S.P. IX, is the adoption of 

 "Mil" (singular), "Mils" (plural), for cubic centimeter (cc.). This 

 coined word, Mil for Milliliter, is more accurate than cubic centimeter, 

 (cc.) for the thousandth of a liter, which the cubic centimeter was intended 

 to express. Throughout this present edition "mil" and "mils" have been 

 used, replacing the less accurate "cc." 



The Families of plants yielding organic drugs have been rearranged 

 in the present volume. The order of arrangement adopted is that which 

 is followed by all botanists of any note at the present time, commencing 

 with the Algae, Fungi, and other cryptogamous growths, the order and 

 sequence of such authors as Engler and Prantl have been practically 

 followed. This has required an entire transposition of the natural orders 

 of the former edition. 



The Chapter on Inorganic Chemicals has been enlarged to meet the 

 demand of many students. Added to this is a brief Chapter on Thera- 

 peutic Action, which is intended as a suggestion to students of how to 

 expand their knowledge in this direction by reference to other works. 



The chapters relating to histological study of plant tissues have been 

 entirely omitted in the present edition in order to economize space for 

 new material, and, secondly, because Professor Stevens, formerly associated 

 in this work, has published an entirely satisfactory volume for class-room 

 work and covered the ground more completely in his "Plant Anatomy." 



A Chapter on Serotherapy has been incorporated which, in treatment, 

 while it is concise, it is hoped will meet the present demand of students of 

 v 



