Medical men have used it more generally for some time past, and since the recent interesting observations and discoveries of our celebrated bacteriologists and histologists all over the scientific world, its use is becoming more general every day, so that the time is not distant when every graduate in medicine will be compelled to be skilled in its use and to use it for diagnostical as well as research work. Pharmacy is keeping pace with her sister sciences of bacteriology, histology and chemistry, and in this particular branch she must not fall behind, for her advances in the decades to come will be along the lines of microscopical work, combined, to be sure, with chemical work. Particularly in these days of close competition in all lines of trade, consequent upon which is the adulteration of products, natural as well as manufactured, is it incumbent upon every pharmacist to be able to detect the false from the true and the adulterant from the adulterated. I feel confident that the pharmacist will not shrink from the use of the microscope as an invaluable aid in enabling him to discover whether he is being imposed upon or not, when it is made clear to his mind that the processes involved in this work are very simple, inexpensive and easily as well as rapidly carried out. If he can be brought to see and appreciate this fact, the time will come when it will be as common to see a microscope in his laboratory as it is to see there his test-tubes, flasks and percolators.

It is not my purpose to enter into details about the mechanism or theory of the microscope, and I will assume that every one is conversant with these. I will hence at once proceed to enumerate what I consider to be the requisites for a microscopical outfit such as will suffice for the examination of any plant, drug or chemical that may come up for examination in the routine of a pharmacist's career. In the first place, a microscope such as will magnify from thirty to five hundred diameters is essential. Then object glasses, one by three inches in size, made of ordinary window glass, cover slips for the same of very thin glass, as can be bought at a very moderate price from almost any optician or dealer in microscopical supplies. A box of twenty-five of these will last for years. Also a razor, which is not an unknown quantity to most men, a few needles inserted in wooden handles to facilitate their manipulation, and a few good-sized corks of good quality. In addition to this are wanted a wash-bottle with distilled water, a watch-glass and a few drop-bottles containing glycerin, alcohol and several dye stuffs in solution to be used as staining agents. For the uninitiated, or initiated too for that matter, it is advisable, if not necessary, to have a book of plates or drawings of sections of all the various drugs as they appear when viewed through the microscope. Unfortunately there are very few of these extant, due largely to the fact that this branch of pharmacy has so long lain dormant. As we advance, however, and the demand increases, books will soon make their appearance "en masse," and among them, I have no doubt, will be found many ex

cellent series of drawings of sections of all drugs, which will enable the pharmacist-microscopist to at once recognize the drug he is examining in section under his microscope.

While working with Professor Flückiger at Strassburg I made the acquaintance of an excellent little collection of drawings of sections of drugs as they appear to the eye when seen through the microscope. It is in French unfortunately, but that does not affect the value of the drawings, which remain the same for all tongues, and is published at Paris by the "Librairie F. Savy, 77 Boulevard Saint Germain," and has as collaborators and editors Professors J. Godfrin and Ch. Noël of the College of Pharmacy of Nancy. It is entitled: "Atlas Manuel de L'Histologie des Drogues Simples," which translated into English reads, "Manual of the Histology of the Simpler Drugs." Mr. Gerock, Prof. Flückiger's assistant and a most excellent microscopist, first called my attention to the book, and Professor Flückiger himself also heartily endorsed it. The cost of the book is a very modest one, being only six francs ($1.25). This constitutes the complete outfit of our pharmacist-microscopist, and it is plain that, outside of the microscope, there is little necessary that a pharmacist has not already in his laboratory.

In regard to the staining agents I shall speak more in detail when I come to the subject of staining the prepared section. Now let us begin cur preparation of the section of a given dry drug that comes up for examination, taking, for simplicity's sake, a root or stem to begin with. We place our microscope on the table before us, facing the source of light-usually a window-and get the mirror at the proper angle to give us the best illumination. Our watch-glass is placed to the right of the instrument, and some water poured into it from the wash-bottle. A small piece of the drug, preferably a small thin root not more than an inch in length, is then immersed in the water and allowed to remain there until it has become quite soft and well saturated with liquid. While this is soaking we take a good sound cork, and with our razor cut it in two through the centre along its longer diameter, being careful to have both cut surfaces smooth. We next take our saturated root and place it between the two pieces of cork, so that it rests between the two flat surfaces of the latter. The upper surface of one of these is lowered below the level of the other, and the top of the root must protrude above the top of the lower piece of cork and below that of the higher piece. It is well to cut off a piece of the root with the razor prior to cutting sections therefrom, so as to have a fresh surface to cut from when we are ready to begin operations. Having this freshly-cut surface of the root just barely protruding above the surface of the lower piece of cork, all being held together between the thumb and first finger of the left hand, we take the razor in the right hand, and with a shearing motion draw the razor across the surface of the root. In this way cut about six or eight very thin sections of the root, all of which will adhere to

the razor.

Next remove these into the water in the watch-glass, and see if any of them are thin enough for use. (They must be decidedly translucent, if not transparent, in order to be fit for use.) If none of them are thin enough, cut some more until one thin enough is obtained. We next place before us one of the already described object glasses, and from our wash-bottle drop a drop or two of water upon its surface. With one of the mounted needles we now place our best section or sections upon the drop of water, and then place over this one of our cover-glasses or cover-slips, as they are generally termed. By slightly pressing upon the surface of the cover-slip with our needle, we now attempt to remove as many as possible, if not all, of the air-bubbles that have collected under the same. This can usually be done, especially by the aid of a small piece of bibulous paper, which too serves to remove the excess of water protruding beyond the edge of the cover-slip. A few drops of alcohol dropped upon one of the edges of the latter and drawn through the liquid under the cover-slip by means of a piece of bibulous paper placed on the opposite side very frequently removes the most stubborn air-bubbles.

Our slide is now ready for examination under the microscope. As the water is very apt to evaporate before the examination is completed, it is well to drop a drop of the same on the edge between the glass and coverslip during the course of the examination. Having adjusted the objective of the lowest power, say 40 diameters, in place, we set our microscope so that it faces the source of light, and then adjust the mirror by looking through the ocular at the field until we are convinced that the entire field is most completely illuminated. We now place our slide upon the objectstand and slide the tube up and down until we can see the section fairly accurately. The final focussing is then done by means of the micrometer screw attached to the side of the tube. With an objective that magnifies about 40 diameters we usually can see all of the section, provided the latter is not broader than one-quarter of an inch, which it should not be to be of practical value. After having taken a general view of the section, we turn to our book of plates and see if any of the latter are similar to or very nearly so to the same. In some cases it is necessary to insert an objective of a higher power and examine certain parts more in detail, and then compare these again with our plate. It may also be necessary in some cases where there are many varieties of the same species, as, for instance, the cinchona barks, to make a longitudinal section in order to decide upon the exact variety, as many of the latter are almost if not exactly the same in cross-section.

As a rule we will not have to resort to staining by staining agents in order to decide what drug we have in hand, but it is sometimes necessary, and always pretty and interesting, to add a few drops of one of our staining agents to fully decide upon certain features of the drug section; for instance, which is cellulose and which is woody fibre, or which is starch

and which inulin or crystals of inorganic salts. This is, however, only a refinement, and not necessary for a decision of what we are examining. The staining agents most generally used and most decided in their action are the following:

Aniline sulphate is used to distinguish woody fibre from cellulose, as are phloroglucine and eosine, while iodine is used to detect starch. These solutions are to be kept in glass-stoppered drop bottles, and one drop dropped therefrom upon the edge between the object glass and cover-slip when used. Aniline sulphate colors the woody-fibre cells brownish-yellow, and leaves the cellulose cells uncolored. Phloroglucine, the preferable one of the three, colors the woody-fibre cells a lovely pink and leaves the cellulose uncolored. Iodine of course, as we all know, colors starch a deep purple-violet and does not color inulin or inorganic salts. There are many other staining agents, but the above will answer all purposes and are usually preferred for botanical microscopy.

At first it will, of course, be necessary to watch and study the plates very closely, making them answer the purpose of an instructor, but soon we will learn by experience and actual observation the characteristics of most standard drugs, and then be able to decide without referring to our plates. By following the method outlined in this paper there is hardly any doubt that almost every one can recognize drugs microscopically, and with a minimum expenditure of time and money. Besides the advantage gained in determining the drug, there is a fascination in microscopic work that will, I venture to assert, take hold of every one who has any desire at all to enter into it, and repay him amply in the shape of enjoyment, satisfaction and pride. In order to facilitate the understanding of those who are unfamiliar with microscopic work, a brief description of the various parts of the plants seen under the microscope may not be out of place. It must be borne in mind that as a rule we have to deal with roots and stems, but that sometimes we are also called upon to examine leaves, pollen and fruit of plants, as for instance: buchu, kamala and anise respectively.

For leaves and fruits, as for roots and stems, we usually take only crosssections for examination, while for pollen and exudates we usually take the substance as it is met with in commerce. In making a cross-section of a leaf it is well to make the same as near as possible to the midrib, which is also