Although it is impossible for all druggists to become experienced with the microscope, yet every one, by a little patience, study, and tact in its use, may learn sufficient to have it serve him often to advantage. One readily admits the importance of such knowledge when he observes that the skilful manipulator, in many cases, shares equal honors with the chemist in determining qualitative (sometimes quantitative) analyses of various substances - in fact, a number of plant-constituents, as starches, oils, acids, sugars, crystals, alkaloids, etc., yield in the hands of chemists and microscopists similar and equally satisfactory results. While it is not the intention here to go very deeply into the subject, it is, however, desired to give that which the average pharmacist, if so disposed, can put with profit into practice. Special laboratory course or various treatises pertinent to this department should be availed of for more extended information.