1890.] MICROSCOPICAL JOURNAL. 225 



and back of the hand, the print of the newspaper,- the web of cloth, 

 etc. iVfter becoming familiar with the changed appearance of such 

 objects when seen under the simple microscope, take up less familiar 

 substances, such as seeds, leaves, roots, powders, crystals, etc. The 

 hairs found upon many of the vegetable drugs are very interesting and 

 instructive — they serve as one means of identification of the substances. 

 After considerable practice the student is ready to take up the alpha- 

 betical list of substances in the U. S. Pharmacopoeia. A simple micro- 

 scope will enable him to observe the microscopical character of a large 

 number of this list. The hairs on nearly all of the leaves are charac- 

 teristic. The warts, wrinkles, ridges, hairs, scales, scars, etc., on 

 branches, barks, rhizomes, roots, and other parts of plants, often serve 

 as a means of identification. Those drugs which consist of whole or 

 parts of flowers are also suitable for examinations. For some of the 

 pharmaceutical preparations, such as mercurial ointment, mercury 

 with chalk, etc., the PharmacopcBia directs the use of a microscope in 

 testing their value. 



The student should not be anxious to handle the compound micro- 

 scope before he is perfectly familiar with the use of the simple instru- 

 ment. 



There are other uses in a drug store for the simple microscope than 

 the examination of drugs, such as the making out of the number of a 

 prescription upon a soiled label. 



When ready to buy a compound microscope, purchase a good stand. 

 This will enable one to add accessories in the future as time, inclination, 

 and financial condition may permit. The cheapest compound micro- 

 scope, suitable for a drug store, costs about twenty-five dollars. The 

 Library Microscope is supplied with one-fourth inch and one-inch ob- 

 jectives, which give a magnifying power ranging from eighty to three 

 hundred and seventy-five diameters. Fifty dollars will secure a very fair 

 outfit, giving one-fifth and three-fourth inch objectives, which are the 

 ones most generally used. It is better to invest about seventy dollars, 

 and secure a good stand with one-fifth and three-fourth inch objectives. 

 Such an instrument will admit of the use of almost any accessories 

 which a pharmacist will ever have occasion to use. As an example of 

 a microscope for this price I will mention the Griflith Club Microscope. 

 Unless a pharmacist feels inclined to be lavish in the investment, it is 

 not necessary to purchase a microscope costing more than from seventy- 

 five to one hundred dollars. 



When commencing it is better to learn to manipulate the stand with 

 eye-piece and objectives before any accessories are added. The books 

 recommended for use in studying the simple microscope are still more 

 serviceable and essential when it comes to the compound. In addition 

 it is advisable to read one or both of the microscopical journals pub- 

 lished in this country: The Microscope oi Trenton, N. J., and the 

 American Microscopical Journal of Washington, D. C. The sub- 

 scription price is one dollar per year, the same for each publication, or 

 $i.8o for the two if ordered from the latter journal. The student will 

 also be interested in the notes on microscopy in the various pharmaceu- 

 tical journals. 



In commencing work with the compound microscope, it is best to 

 follow the same plan as suggested for the simple — to first study familiar 



