While the author does not feel that he should surrender his judgment as to the importance of various remedies to that of the Committee on Revision, he does believe that official substances should always be tav ored by the physician when not to the detriment Of the patient. More over, for obvious reasons, it is important that a text-book for students should recognize the legal authority of the country on the subject of drugs: Therefore, while it has been deemed advisable to consider a number of unofficial drugs, because of their practical importance, it has also been necessary to include some substances of little remedial value because of their recognition by the Pharmacopoeia. One innovation in the U. S. Pharmacopoeia which has been fol~ lowed in this work is especially worthy of note. That is the adoption of the British term mil for the thousandth part of a liter. This is a much more convenient as well as a more accurate term than the cumbersome C.c.