PART I GENERAL CONSIDERATIONS CHAPTER I THE MICROSCOPE IN MODERN PHARMACY The Federal Pure Food and Drugs Act went into effect June 30, 1906. The act is enforced by the Bureau of Chemistry of the U. S. Department of Agriculture. The Bureau has adopted the U. S. P. (United States Pharmacopoeia) and the N. F. (National Formulary) as the legal standards of the quality and purity of drugs. The U. S. P. IX contains the microscopic descriptions of the crude as well as of the powdered vegetable drugs and no pharmacist can use the legal drug standard intelligently unless he has had a thorough course in drug microanalysis in a well equipped laboratory. The language and terminology descriptive of the drugs and remedial agents mentioned in the U. S. P. and the N. F., constitute the "purity rubric." It soon developed that the legal descriptions and definitions were defective in many ways, as will be more fully set forth in Chapter III of Part I. Controversies have arisen as to the interpretations to be put upon some of the drug descriptions and as to what constitutes wholly negligible and unimportant accidental additions and admixtures. The introduction into the U. S. P. of the microscopic descriptions of vegetables has had the effect of greatly increasing the legal value of the drug descriptions. A very brief introduction into the history of the use of the compound microscope in pharmaceutical practice is not out of place. The progress in histological investigation, animal as well as vegetable, has kept pace with the progress in the manufacture of lenses for simple and compound microscopes. In other words, histology had its birth with the discovery of the microscope and has become perfected in direct ratio with the improvements in the artificial aids to vision. The microscope in its earliest and simplest form consisted of a convex lens of some transparent substance. Magnifying lenses were known long before the discovery of glass. The wise Seneca (first) century), who was apparently well versed in the properties of lenses, states that the ancients noticed that writing viewed through glass |