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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.

PRACTICAL USE OF THE MICROSCOPE IN PHARMACY.

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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:

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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

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to be included in the section. Let us take as an example of a root pareira brava and of a leaf a coca leaf—(see illustrations). These drawings I think point out nearly all of the varieties of cells and organs to be found in the plant. The difference in the various drugs will be found to consist largely, if not entirely, of the different arrangement of these various cells and organs. What the use and value of these various cells and organs are to the plant I will not discuss here, as that falls in the domain of botany rather than of microscopy. If I have by means of the above paper succeeded in inducing some of the many pharmacists before me, or scattered throughout the broad confines of our great country, to make their first attempt at microscopical work, I shall feel amply repaid for my efforts, for it will only require the first effort to make a microscopist out of any of you or them ; if not a microscopist, certainly a microscopical enthusiast, which will before long cause you to become a full-fledged microscopist.

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Two of the samples of oleic acid used in the following experiments were obtained in the market; the first was of a dark reddish-brown color, disagreeable odor, and acrid taste; the second was of a dark straw color, and of a more pleasant odor and taste than the preceding; the third sample was manufactured from white castile soap, as follows:

One hundred grams of soap were dissolved in 1000 c.c. of water, and tartaric acid added in slight excess. The liberated oleic acid floated upon the surface in a cream-colored mass; the water was decanted and the mass washed twice. The mixture of fatty acids was kept at a temperature of o° C. for twelve hours, when the greater portion of the palmitic and stearic acids separated and were removed by straining. This yielded an acid of a very light straw color and much pleasanter odor and taste than any found in the market.

Oleates of mercury were next prepared according to U. S. P.

No. I was made from best commercial sample of oleic acid. The resulting oleate was a liquid of a dark straw color, and within a week contained a large deposit of metallic mercury.

No. 2 was made from the darker colored commercial sample of oleic acid. It was a light-brown colored liquid of a syrupy consistency, gradually becoming darker on standing, and in a few weeks contained a heavy deposit of mercury.

No. 3 was made from the oleic acid from soap, contains 10 per cent. of yellow oxide of mercury, and prepared according to the German Pharmacopoeia about as follows: Triturate the oxide of mercury with an equal weight of alcohol in a tared capsule. Add the oleic acid and triturate

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