50 THE AMERICAN MONTHLY [March, 



there remains a large proportion whicli requires the use of the micro- 

 scope. Medicinal leaves, closely resembling each other, can be distin- 

 guished by a microscopical examination of the hairs found upon their 

 surface ; as an example, we take mullein leaves, which are thickly 

 covered with beautiful stellate hairs, aconite leaves are sometimes adul- 

 terated with mullein leaves, but the stellate hairs enables the simple 

 microscope to show the difference, even after the leaves have been 

 pressed and otherwise mutilated. The hairs found upon aconite leaves 

 are less numerous than the mullein hairs, and further distinguished from 

 them by not branching. The fissures, ridges, warts, hairs, scars, etc., 

 found on barks, leaves, rhizoms, woods, and other parts of the plants 

 employed in medicine, are physical characteristics which can be dis- 

 tinguished by means of the simple microscope, and aid the pharmacist 

 in recognizing vegetable drugs. 



c. The simple microscope again comes into plav for the pharmacists, 

 while examining many of the medicinal preparations, in order to deter- 

 mine their quality or prove their identity. In some instances, the 

 United States Pharmacopoeia prescribes that the simple microscope 

 should be used in testing the quality of preparations ; as an example, 

 we have the ordinary mercury ointment, which is a mixture of metal- 

 lic mercury with animal fats. The Pharmacopoeia states that this should 

 be mixed until the globules of metallic mercury cannot be distinguished 

 by means of a microscope magnifying ten diameters. 



d. The simple microscope may also be made serviceable while 

 testing the quality of some of the utensils used in a pharmacy. As a 

 case comes in point, \ve cite the examination of sieves to see that they 

 have the proper number of meshes to the linear inch. Some of the 

 finer sieves would require the use of the compound microscope, while 

 the simple microscope will answer in the examination of the coarser 

 sieves, which are more commonly used. 



e. The simple microscope is a convenience when attempting to 

 make out a prescription number upon soiled labels, which pharmacists 

 receive when prescriptions are to be refilled. It is also convenient in 

 the examination of bills which are suspected of being counterfeit. It 

 can be used when it becomes necessary to remove a sliver of wood 

 from the flesh, and there are a thousand and one instances where the 

 pharmacists can conveniently make use of the simple microscope. 

 Some of the insects which infest drugs are appropriately studied by 

 means of the simple microscope. Customers may also be interested in 

 the instrument, and its use is then turned to a commercial advantage 

 by drawing trade. 



\_^To becontimiedJ\ 



Adulteration of Lycopodium. — Talc, gypsum, resin, dextrin, 

 starch, sulphur, pine-pollen, sand, tumeric, and various sporules have 

 been used. Dr. Whelpley recently examined and found three speci- 

 mens to be pure with the exception of accidental traces of vegetable 

 tissue. He says : The drug is best examined with a power of about 

 one hundred diameters. The specimens examined by reflected light 

 show better than those in liquid. However, it is advisable to use both 

 methods. Macerate for some weeks in glycerin, and mount in glycero- 

 gum for examination by transmitted light. 



