organic matter, clings to all subterranean plant organs. This makes it evident that some sand will be found upon many crude drugs and mixed with the powders made from them, as there is no means of removing it entirely, even with the most careful washing and winnowing. We would naturally expect to find more sand with the powders of roots, rhizomes and tubers; less with barks, and still less with most herbs, flowers and fruits. It should be wanting in powders of peeled barks, of woods, of peeled roots, rhizomes, tubers and seeds.

2. Dirt, Clay, Lime.-Not infrequently collectors leave enough dirt attached to subterranean plant organs as to amount to adulteration, as, for instance, Mexican sarsaparilla and many of the roots and rhizomes collected in the United States. Clay is sometimes added to powders (goa powder). Valerian is very likely to contain an excess of clay. Lime is not intentionally added, but it will be found in powders made from limed crude drugs, as iris, ginger and nutmeg.

3. Substances Much Used for Purposes of Adulteration.

To enumerate all of the substances which may be used for the purpose of adulterating powdered spices and vegetable drugs is impossible. There are, however, certain substances which are used more than others and these should receive especial consideration and study. Based upon many years of experience in the microscopical examination of the class of substances named, the following materials are given as being most commonly employed for the purpose of adulteration.

1. Ground olive pits and nut shells.

2. Ground coco nut shells.

3. Clove stems and allspice stems.

4. Peanut shells.

5. Cereals (roasted, ground and broken), wheat flour, rye flour, barley flour.

6. Corn meal, corn starch, corn cobs.

7. Sand. Small pebbles.

8. Dirt, clay.

9. Mallow leaves. Willow leaves.

10. Beans and peas.

11. Curcuma.

12. Milling refuse and screenings.

13. Trimmings, fragments, etc.

Microscopically these substances are quite readily recognizable and the student is advised to secure samples of the materials listed and to make a careful microscopical examination of them. It may be stated

that these common adulterating substances are more likely to be found in spices than in vegetable drugs.

The substances and combinations of substances which are occasionally used for purposes of adulteration is legion. Rocks, shot, pieces of lead and iron, pressed and baked clay, saw dust, colored starches, colored and loaded plant tissues, spurious roots, barks, woods, leaves, fruits and flowers have been used. The analyst must not be surprised at anything, because the unexpected is constantly revealed. Special forms or kinds of adulterations are constantly changing. Old familiar methods disappear and new methods appear. The additions of some coloring agents, as Prussian blue, indigo, is falling into disuse. Elm bark is now rarely adulterated. Hydrastis, despite the high price, is rarely adulterated. False crocus is not often found. Imitation coffee beans and nutmegs are becoming extremely scarce. Practices of adulteration vary and shift geographically with changes in the thoroughness or laxness with which the pure food and drug laws are enforced.

4. Commonly Adulterated Powdered Vegetable Drugs.-The following powdered vegetable drugs and spices are very frequently adulterated:

Aconite-Stems and foreign species.

Asafoetida-Vegetable tissue, starch, mineral matter, etc.
Belladonna L-Foreign leaves.

Belladonna R-Phytolacca root.

Benzoin-Bark impurities.

Marjoram Leaves of related plants, mallow leaves, etc.

Mustard-Cereal and curcuma.

Pepper (black)-Refuse, nut shells.

Pepper (white)-Cereal, bleached.

Pilocarpus-Spurious leaves.

Pyrethrum (insect powder)-Entire herb used. Related species used. Stems used.

Sage-Foreign leaves and herbs. Dirt.

Sarsaparilla-Crowns, stems.

Spigelia-Ruellia ciliosa.

Valerian-Dirt and clay.

5. Pebbles, Lead, etc.-Such substances are not commonly employed, and are nearly always added to crude drugs. Pebbles are often added to coffee beans and to senna. Shot, pebbles, lead foil, etc., have been found in the interior of lumps of gum opium. Stones have been found in the interior of bundles of sarsaparilla and other bundled crude drugs.

6. Coloring Substances.-The desire to place an attractive article upon the market has led to the pernicious habit of coloring certain drugs. We have already referred to the habit of liming, which does serve some useful purpose besides giving a white color. In certain parts of China tea is quite generally colored with indigo and Prussian' blue. Coffee beans are similarly colored. Adulterants are oftent colored before adding them to the drug in order to simulate the normal color.

Bleaching, liming and otherwise changing the color of drugs, crude or powdered, in order to hide inferiority, is contrary to the law and cannot be too strongly condemned.

IV. THE DETECTION OF ADULTERATIONS

The practicing pharmacist should not take the purity of an article for granted, but should satisfy himself to that effect personally. Every drug as soon as received should be inspected carefully to determine whether or not it is the drug intended, as some mistake may have been made in the order, in the packing, labeling or shipping. The drug should then be carefully examined to determine its purity and quality, and in order to do this the pharmacist must be thoroughly familiar with the characters of the normal drug. If the drug is not of standard quality it should be returned to the shipper.

In the case of powdered drugs the matter becomes more difficult. The intelligent use of a good compound microscope is absolutely necessary. The student must have a thorough knowledge of vegetable histology. He must know the normal tissue elements in order that he may recognize the presence of foreign elements. The recognition of the adulterant is of prime importance; its identity is of lesser importance as a rule. In many cases it will be found very difficult, if not impossible, to determine the identity of the sophisticant. The quantitative determination of the sophisticant is also quite difficult.

CHAPTER VII

THE MICROSCOPICAL EXAMINATION OF POWDERED

VEGETABLE DRUGS

I. EQUIPMENT AND METHOD

The ability to identify powdered vegetable drugs and their adulterants will depend largely upon the intelligent use of a good compound microscope and the necessary accessories and reagents. It is further evident that the study of the histology of crude drugs is a necessary preparation to the study of these drugs in the powdered state. In the powders the cells and cell-contents appear broken and intermingled. This fragmentary state of tissue elements renders their identification more difficult as compared with these elements as they appear in carefully prepared sections of crude drugs.

As already indicated, the fineness of the powders varies greatly. For examination under a compound microscope Nos. 60 to 100 are most suitable. No. 80 is, perhaps, the fineness best suited in the great majority of cases. A No. 100 is generally too fine and a No. 60 is somewhat coarse. Very coarse powders must be further reduced by means of a pestle and mortar. For low powder examinations powders from 40 to 60 fineness are very suitable.

The equipment and apparatus required by the micro-analyst is comparatively inexpensive, yet it is very earnestly advised to secure only those appliances which are useful or essential for the work in hand. The following list is submitted without entering into detail, as it may be assumed that the microscopist does not require detailed explanations:

1. Simple lens.

2. Compound microscope.

(a) Ocular with micrometer scale.

(b) Oculars, Nos. 2 and 4.

(c) Objectives, Nos. 3, 5 and 7.

3. Slides and covers.

4. Section knife or razor, and strop.

Safety razor blades may be used.

5. Polarizer, for the study of starches, crystals and other substances.

Should be convenient to use. The selenite plates are useful.

6. Accurate metal or hard rubber millimeter ruler for measuring crude drugs, fruits, seeds, etc.

7. The required glassware and adjunct apparatus.
8. The required reagents.

9. Equipment for making moisture determinations. 10. Equipment for making ash determinations.

The laboratory in which the work is done must be roomy, welllighted, provided with the necessary shelves, apparatus and supply cases, reference books, etc. The analyst must see to it that the necessary things are provided. A skillful worker should have the tools of his choice.

It is impracticable to enter into a full discussion of the technique and methods to be employed by the micro-analyst. The following suggestions will serve as a guide to methods of procedure.

For microscopic examination a pinch of the powder is mounted in some clearing fluid. Heat may be employed to remove air bubbles and to increase the translucency. The student is at first greatly confused by the optical picture which presents itself. Cell-fragments and cell-contents are variously intermingled with various cell-groups, but this confusion vanishes with experience and with the knowledge of the histologic structure of plants. With the exception of very fine meals, it will be found that cells occur in groups, the number of cells in each group depending upon the fineness of the powder and the size of the cells. Bast cells, trichomes, tracheids, wood cells, ducts and other elongated elements appear in longitudinal view. Tabular elements, as epidermal cells, appear in surface view. The more delicate elements, as meristem cells, leaf parenchyma, pith cells, ordinary isodiametric parenchyma, are usually pretty well broken. Sclerenchyma cells are rarely broken and belong to the strikingly characteristic elements noticeable in powders; the same may be said of the short thick bast cells found in cinchona, cinnamon and some other drugs. Hair cells, epidermal cells and pollen grains are quite diagnostic. Glandular structures are of little significance in the examination of powders, as they are usual'y too much broken. Cell-contents are very important, especially the starches and the crystals of calcium oxalate. Starch granules usually appear entire, likewise the crystals of calcium oxalate, excepitng the large crystals, as they occur in scilla, rhubarb, soap bark, orris root and in a few other drugs, which are more or less broken in the powdering.

1

It is rarely desirable or necessary to use many micro-chemical reagents in the study of vegetable powders. An intelligent use of a suitable clearing fluid, a solution of chloriodide of zinc and a 150 normal iodine solution is about all that will be required. To hasten 1 A mixture of equal parts of glycerin and water will be found most useful.