Earth Air Fire and Water
The Pharmageddon Herbal
Chapter 8A
Ivor Hughes

Introduction to Materia Medica
-::-::-

Introduction
From the wisdom chest of the past we may pluck the pearls of the future. By looking at the past we may clearly see where we are going. By looking at the past we may clearly see the sign posts that led humankind on its path of great wanderings.

We may clearly see, where we were halted, and had to take another road. After all, the urge of the specie is �Survive� That is a primal command.

Only 50 years ago things were so very different, in terms of the health and the vigour of the Western style populace at large.

We have fallen a long way.

Current developments, in the Medical, Biological and Agricultural Sciences, when viewed against the backdrop of where we are as a specie, both ethically and spiritually, is alarming.

Our Materia Medica is formed from the accreted wisdom of the past. Untold millennia that recede much further than the evidence of the 60,000 year old Shanidar burial site.

The Materia Medica is the peoples heritage, the legacy of the past. A great gift from the Ancestors. It is under threat from those that would take it, and then restrict access.

The Materia Medica 8.1
In its modern sense, the term �Materia Medica�, is defined by �Blacks Medical Dictionary 34^th Edition�, as �that branch of medical study that deals with the source, preparation and use of drugs�. In its literal sense, and as it was understood, it means medicinal materials. Accordingly, the materia medica is the core of all systems of medicine, differing only in the type of material of which it is composed. The formulation and use of Herbal materia medica would require knowledge and expertise in the following areas;

A. Pharmacognosy
In orthodox medicine, Pharmacognosy was an essential branch of Galenic Pharmacy. It is a descriptive science that requires a good knowledge of botany and biology. This is applicable to the drug plant in its living form, e.g. its wild habitat, its life cycle and collection times. Every Apothecary had a network of harvesters, who in the course of the season, would steadily fill the drawers and jars and bottles that stocked the village medical centre.

However, when the drug plant arrives in the laboratory or pharmacy, it is usually in its dried form, and the task of identification becomes more exacting. It will be appreciated that the dried plant, or plant part, will have a very different appearance to that of the fresh plant, therefore, a good knowledge of plant morphology is essential. Morphology is the study of the plants shape or form, e.g., root, leaf, stem, flower, etc.

In the event that the material is grossly distorted from the drying process, or is shattered, granulated or powdered, then knowledge of plant histology is needed. Histology is the study of minute structures of organic tissue. The moderately magnified material, will be compared with a known true sample, and examined for foreign material, and also for evidence of deliberate adulteration.

B. Pharmacology
Is the knowledge of the action, the fate and the excretion of drugs when they are introduced to the living system. The Shaman is a master of pharmacology.

C. Toxicology
Literally, a knowledge of the toxic effects of poisonous plants on the living system, and where known, the antidote and treatment. We have very good empiric (folk) knowledge that informs us of which plants and which stones are helpful or harmful.

D. Posology
The word is derived from Greek, meaning �how much�, and refers to that branch of medical science that determines the safe functional dose of a substance. It will take into account such variables as age, gender, weight, racial type, and any acquired or natural tolerance. This must also be balanced against idiosyncrasy or allergic intolerance. It will also take into account the route of administration, which has a direct bearing on the speed of action and degree of absorption. I speak of course, from the days of Physician/Pharmacist. Today you will only find standardization in orthodox medicine.

E. Herbal Apothecary.
The preparation, compounding and the dispensing of plant based drugs.

There are various fragments of materia medica from the ancient Babylonian and Egyptian eras. Examination of the medical recipes show a fine grasp of the knowledge required of a sophisticated system of medicine. It cannot be simply brushed aside, as magical mumbo jumbo.

Some of the recipes contained animal and insect parts, while others contained faeces from various sources. In the past it has been the trend, in orthodox medical circles, to dismiss such formulations as gutter or sewer pharmacy, while ignoring the obvious parallel with modern Sera and vaccines. However, today a more enlightened interpretation of the evidence is steadily gaining ground, e.g.,

                                                                                                       Doctor Joseph Needham
                                                                                                      �Science and Civilisation in China�.
                                                                                                       Vol. 5 Chapter 15 Cambridge.

The most famous of the Egyptian medical writings, is the so called �Ebers� papyrus, which has been dated Circa 1550 BC. Over 3,500 years old, therefore, we must avoid the trap of confusing technology with intelligence, or considering scientific theory to be superior to empirical knowledge, because clearly it is not.

The Raw Materia Medica 8.2
It is not an overstatement to say that herbal therapeutics represents the predominate medical system. Circa 4 billion people rely upon herbs for their primary health care. Medicinal herbs are the heritage of all cultures and old civilisations; and for many of them, a direct lineage can be traced by cross fertilization.

Samarian - Persian - Assyrian - Babylonian - Mosaic -Egyptian - Greek  -  Roman - Chinese - Arabic - Celtic.

Today the rich tapestry has resolved itself into four major strands, A golden thread, where natural medicine is practiced as both an art and a science.

Chinese - Islamic - Ayurvedic/Unnani and Neo-Western.

The major schools are like beads on a string, elective, both in system and raw materials. Between them they are able to muster around 6,000 plants of known therapeutic activity. No other system of medicine can command such a flexible and wide ranging materia medica. And one that circumvents the modern problem of racial idiosyncrasy.

The figure of 6,000 plants must be viewed in context. Of the estimated 250,000 members of the angiospermidae (flowering plants), less than 5% have been screened for medicinal substances. The majority of that 5%, have only been screened for a single substance , e.g., an alkaloid; on that basis alone, we can be assured that, even with a written history of almost 4,000 years, the art is still in its infancy and that, like an iceberg, much lies hidden.

All our needs in nature are catered for, if that were not so, we could not have survived as a specie. When a correctly prepared herbal medicine, fails to achieve its goal, it is not the efficacy of the herb, that is called into question, but rather the accuracy of diagnosis and method of treatment. However, that is a problem that is common to all systems of medicine. There is no evidence to suggest that high tech diagnostic techniques achieve a greater accuracy than those obtained by a sensitive natural healer.

Crude Vegetable Drugs 8.3
For the purpose of this text, the word �Herb� should be taken to mean �all of those parts� of the plant kingdom, that we utilize for medicinal purposes. All such substances, when in the natural or dried state, are referred to officially as �Crude� drugs, i.e. drugs that have not been converted to a form, that ensures maximum safety, and individual precision, on the part of the prescriber.

Table 8.3A Crude Drugs.

All of the above plant parts are classified as �Organised� drugs, in that they have a well defined cellular structure. Another class of crude drugs is the exudations;

Table 8.3B The Exudations.

The substances in Table 8.3B, are said to be "Unorganised�, meaning that they do not have a cellular structure.

A further important class of substances are the Bee �APIS� products;

Honey - Wax - Propolis - Pollen.

The honey, wax and propolis, are classed as exudations and have unorganized structures. Pollens, as gathered by bees, are the fertilizing spores of flowering plants, and have an organized structure. The structure of the crude drug will determine its processing route.

The Evaluation of Crude Drugs 8.4
The evaluation of a crude drug is an essential part of Pharmacognosy. The individual drug plant would undergo all, or some of the following procedures;

1.Organoleptic Assessment, which is inclusive of the following;

                                              A - Smell - e.g. is it characteristic of the material?
                                              B - Sight - e.g. color, shape, i.e., macroscopic appearance.
                                              C - Taste - e.g., sweet, sour, astringent, spicy, etc.
                                              D - Touch and sound - Condition and moisture content.

2. Microscopic Assessment, usually for powdered drugs. Its histological appearance must match that of a known sample, and the % of adulteration with foreign substances noted.

3. Chemical and Physical Testing, physical constants, such as melting points (mp), boiling points (bp), specific gravity (sg), solubility; and optical rotation, such tests are used extensively with drug constituents, e.g., volatile and fixed oils, alkaloids and glycosides. Chemical methods will include thin layer chromatography, ash tests, water and ethanol soluble extractive values, heavy metal tests etc.

In these days of increasing specialization, such tasks are no longer performed by the pharmacist. However, they must be able to predict incompatibilities, solubilities and therapeutic dose, and advise in such matters.

Herbal Constituents 8.5
In utilizing herbs for medicinal purposes, empirically and scientifically, it is the practice to use those parts that contain the greatest amount of �active constituent�, the chemical entity that elicited a major pharmacological response, e.g., cathartic or analgesic effect. Herbs produce every known pharmacologic response.

The active constituent levels, in the families of plants that contain them, are a function of known variables and from that, a plus/minus % for those levels can be known.

It is now recognized that the overall synergy of a plant is more important than the level of a single constituent. Quite obviously, a plant medicine must be standardized in some way, so that a safe functional dose may be prescribed. There are four main methods.

1 - By Chemical Assay � This involves the separation of the known constituents. The concentration is determined and adjusted to a specific potency, based on the original concentration. This totally destroys the synergy of the plant.

2 - By Biological Standardization. - This method is usually reserved for potent drugs, where a chemical assay is not possible or is unreliable, for example, Digitalis, (Foxglove). The assay carried out by utilising the LD. 50 test (Lethal Dose: 50%). A number of experimental animals are used to determine the minimum dose required to kill 50% of the creatures, within a defined period of time. Such tests are not precise, due to the differing metabolism of humans and the animals, and also human idiosyncrasy, as may be observed by the high rate of toxic effects of digitoxin, when administered to patients of the same size and weight as each other. It need hardly be pointed out that this method involves extreme cruelty. The synergy is again destroyed.

3 - By Physical Standardization. - This method is usually combined with the chemical method and takes account of boiling point, melting point and specific gravity. Once again, the level of 1 or 2 known constituents are adjusted to a specified level of activity. The synergy of the plant material is destroyed.

4 - Arbitrary Standardization. - Is carried out by adjusting a liquid extract to volume, whereby 1 millilitre of the extract is equal to 1 gram of the air dried herb. Obviously, the quality of the herb is the only variable when that method is used. The synergy remains intact.

Ethical considerations, to one side, and from the standpoint of natural medicine, methods 1, 2, and 3, are not acceptable, because the natural synergy of the herb has been destroyed. It is well known among Galenic Pharmacists, that extracts and tinctures prepared by arbitrary standardization usually display a higher level of activity than would be expected from the known concentrations of the so called active principle. In clinical practice, they also display a more acceptable and predictable pharmacological response than assayed products.

A Brief Description of Herbal Constituents and their Solubility's in Alcohol and Water, 8-6

Before proceeding to a description of the carriers and solvents employed in pharmacy, it will be helpful to review the major compound constituents of herbal drugs, and their solubility's in alcohol and water.

Alkaloids 8.7
The alkaloids as medicinal substances represent the largest class of drugs to be found in the plant kingdom. The majority of alkaloids so far discovered, have been isolated from the �Angiosperm�, or flowering plants. Commercially, the alkaloids, because of their medical, commercial and toxic properties, are extremely important to the human economy.

They are naturally occurring nitrogenous bases, and are combined with acids as salts. So they are said to be �basic� in that they are on the alkaline side of pH7.

Some cultures �free base� alkaloids by adding some slaked lime or a substitute to the botanic chewing quid.

Alkaloids may be solids or liquids. The majority of the known alkaloids are solids, in addition to nitrogen, they contain carbon, hydrogen and oxygen.

Generally, the alkaloids are freely soluble in alcohol or diluted alcohol, but only feebly so in water, however, if the alkaloid has been precipitated as a salt, they become freely soluble.

Most of the alkaloids are sensitive to heat. The alkaloid containing drugs should not be exposed to temperatures exceeding 60�C.

Therefore, the practice of preparing infusions or decoctions from alkaloidal herbs is a dubious procedure; because the resulting changes may render the alkaloid liable to hydrolysis (decomposition), or it may be converted to an isomeride, which is a compound which has the same kind of atoms, in the same proportions, but are arranged differently. This changes the chemical and physical properties of the original compound. In some cases, both reactions may occur together, thus the synergy is irretrievably destroyed.

Anthraquinone Derivatives (Emodins) 8.8
Emodins are found in the anthracene group of the vegetable purgatives, or cathartics. Members of this group display widely differing modes of activity. While there is no doubt that Emodins have a laxative effect, it is generally considered that the differences are due to other more complex substances, such as glycosides, which yield emodin. Emodins are widely distributed throughout the vegetable kingdom in plants that exhibit no noticeable laxative effect. Anthraquinone derivatives are soluble in both water and alcohol. Some are stable to temperatures of up to 100�C, while others will decompose at temperatures in excess of 60�C. In view of that fact, it would be prudent to treat the Anthraquinone as thermolabile.

Albumins and Globulins 8.9
The albumins and globulins belong to a class of substances known as proteins. The proteins are the primary component of all living mater. From a medicinal view, they are considered to be ballast, or inert substances. Invariably, they are subject to putrefaction, the breakdown products render preparations containing them, unstable and unfit for human consumption. Their exclusion from medicinal substances is desirable. Generally, the albumins are insoluble in alcohol and soluble in water. The globulins are insoluble in both, therefore, they may be precipitated from an alcoholic solution and removed by filtration, rendering a Galenic preparation stable.

Chlorophyll 8.10
Chlorophyll is a green pigment that is to be found in the leaves and stems of plants. It traps the sunlight for the photo synthetic process, this enables the plant to produce starch, without which, we could not exist. Medicinally, it is claimed that chlorophyll is a mild bactericide with deodorant properties. For the natural therapist, it is a chelation compound of extraordinary efficiency, it assists the body to excrete heavy metals and also to dissolve kidney stones, therefore, its presence in medicinal preparations is to be encouraged as a detoxifier. Chlorophyll decomposes in water, but is soluble in alcohol.

Cellulose and Lignin 8.11
Cellulose stiffens the cell walls of plants and provides support. As a substance, it is classified as a polysaccharide, and forms an expandable primary wall for the cell.

Lignin forms the secondary cell wall, which grows when the cell has matured. The primary function of lignin is for stiffening and support, and is present in all shrubs and trees. Cellulose and lignin are insoluble in alcohol and water. Medicinally they are considered to be inert, and are discarded on completion of the extract process. However, the Spagyric School considers that view to be incorrect, and further recover the salts from the cellulose and lignin, which is then added to the final extract.

Fixed Oils 8.12
Fixed oils are only slightly soluble in alcohol and insoluble in water. Generally, fixed oil, when present in material which is being extracted, interferes with the process, e.g., strophanthus seeds, which are defatted prior to extraction.

Flavonoids 8.13
The therapeutic status of flavonoids has still not been settled. In older medical literature they have been classed as vitamin �P� (P for permeability), however, studies have shown that little or no flavonoid is absorbed by the intestinal tract, which does not support the vitamin theory. They are bio-active and are biologically classed as co-enzymes, many of which are known to catalyze the hydrolysis of glycosides, unless they are rendered inactive. Flavonoids are thermolabile, and destroyed by temperatures exceeding 60�C. They are inactivated and soluble in aqueous solutions of alcohol.

Glycosides 8.14
The glycosides are widely distributed in nature and display a diverse range of physiological action. As a class of compound, they are notorious for their susceptibility to hydrolysis. The breakdown products are either inactive or medicinally less active. As a general rule, they are heat sensitive and soluble in alcohol and water. The saponins, as with the other glycosides, are prone to breakdown. They are unstable in water based preparations, while the alcoholic based solutions are less prone to hydrolysis.

Gum Mucilage 8.15
The natural gums are a class of vegetable products that are insoluble in alcohol and soluble in water. Medicinally they are inert. They provide a good growth medium for mould spores, for example Agar-agar is a common culture medium so it is desirable that they be removed from medicinal preparations, if decomposition is to be avoided.

Resins 8.16
The resins may be divided into three main groups;

1. The True Resins are usually solids and non volatile, e.g., Colophony and Copal. They are soluble in alcohol and volatile oils, but insoluble in water.

2. Oleo-resins and Balsams. The oleo-resins are a mixture of resin and volatile oils. Those products, which also contain benzoic and cinnamic acids, in addition to the resin, are usually designated as balsams, e.g., copaiba and Balsam of Tolu. They are soluble in alcohol but not in water.

3. The Gum resins form an important group of medicinals, e.g., Asafetida, Galbanum, Gamboge, Myrrh, Olibanum and Scammony. Many of the gum resins also contain volatile oils. The gums are usually completely soluble in water, but insoluble in alcohol. The resins and volatile oils are soluble in alcohol (90%), and insoluble in water. The gums are precipitated from solution by the alcohol.

Starch 8.17
Starch is a white proto-substance found throughout the vegetable kingdom. It is classed as a nutrient, but medicinally inert. It is to be found in barks, roots, rhizomes, leaves and seeds. Starch is insoluble in alcohol, but soluble in boiling water. When present in an alcoholic menstruum, it forms a precipitate that may be removed by filtration. Aqueous solutions are prone to spoiling and growth of micro-organisms.

Tannins 8.18
The vegetable tannins are widely distributed in the plant kingdom. Chemically, they have been divided into three groups. Medicinally, only the group known as �Phlobatannins� are important. Tannins are a major cause of incompatibility in herbal preparations. They can form insoluble complexes with the heavy metals, alkaloids and glycosides, therefore, it is not advisable to combine a tannin containing herb with others of a different type. Tannins are soluble in alcohol, water and glycerine.

Volatile Oils 8.19
The essential, or volatile, oils are a further class of product, which are extensively distributed. They are obtained from barks, flowers, fruits, grasses, leaves, roots and wood. They consist of complex mixtures of organic chemical compounds, and are freely soluble in alcohol 90%. They are slightly soluble in water, and insoluble in glycerine. The volatile oils themselves also have solvent powers, particularly of organic fats and waxes.

Waxes 8.20
The waxes, are esters of fatty acids, as are the fixed oils and fats. The major difference is, that the alcohol represented in the waxes is not glycerol. A number of plant waxes also contain paraffin hydrocarbons. They are insoluble in water and glycerine, sparingly soluble in alcohol, and soluble in chloroform and ether.

Solvents used for Extraction Purposes 8.21
The purpose of a solvent is to remove from a solid, either in part, or in its entirety, such substances that may be rendered to a liquid.

In chemistry the solvent is known as the �Solution�, and the extracted material as the �Solute�. In Apothecary work, the solvent used for extraction is referred to as the �Menstruum�. When the material has been extracted, the menstruum is known as the �Vehicle�, or �Carrier� of the extracted material.

The use of solvents, allows quite precise manipulation of herbal material; without their use, herbal therapeutics would not have advanced far beyond a primitive art. Solvents of various kinds are in widespread use throughout industry and in most households, in the form of stain removers and oven cleaners, washing powder and liquids

Solvents differ widely from each other, not only in differing boiling points, but how they act, or react, with substances in which they come in contact. In order to maintain the synergy of herbal preparations, it is vitally important that the plant compounds do not decompose, dissociate or complex, when in contact with a solvent.

Basic Chemical Reactions 8.22
If we include synthetics, there are around 10 million known compounds. The number of potential chemical reactions between them is so large, that one must calculate in astronomical numbers. To emphasize the complexity involved, let us assume that a herbal material contains 50 compounds, and the action of the solvent causes the compounds to split from each other and then recombine in units of 5; the number of possible combinations of 5 compounds is 2,118,760. In point of fact, all essential oils, which represent a very small percentage of the total plant complex, most of which contain hundreds of compounds. So let it be clearly understood, that in the scientific sense our knowledge is meager in the face of such exquisite natural structures.

Incompatibilities in Herbal Preparations 8.23
The list of possible incompatibilities is endless, and it is only by extreme care that the major problems can be circumvented. The compound complexity of a single plant, when introduced to the biological complexity of the human system, and the resulting reaction from that combination, is a major problem for the Pharmacologist.

Contrary to popular perception, the fate and excretion of a plant drug, when introduced to the biological idiosyncrasy of an individual, is far from settled. The five basic chemical reactions are not limited to the test tube, but are an integral part of our human economy.

For those reasons, the Apothecary must view the practice of poly-pharmacy (2 or more drugs), with a critical eye. In the event of an adverse reaction from the administration of a compound remedy, the therapist is faced with the task of eliminating the offending substance, or substances. To prescribe one that is not of an impeccable empirical character, is irresponsible, unethical and could dangerous. 

Incompatibilities 8.24
An incompatibility may be said to exist, when an unintended effect occurs with a herbal preparation. For convenience, the incompatibilities may be placed under four headings;

A. Chemical. B. Physical. C. Pharmaceutical. D. Therapeutic.

Chemical Incompatibilities 8.25
When the combination of two or more herbs, and the solvent, or one herb and the solvent, react upon each other in such a way, that the efficacy or safety of the preparation is interfered with, then a chemical incompatibility has occurred. This is common, and represents the greatest number of problems for the Apothecary. The combination of two or more herbs can produce;

                                               1. A combination reaction. (glycosides subject to hydrolysis)
                                               2. A single replacement reaction. ( in presence of mineral acids)
                                               3. A double replacement reaction. (alkali�s and enzymes)

As a general rule, herbs should be prepared and prescribed on their own. Poly-pharmacy has long since been discredited, yet herbal preparations of incredible proportions, are still to be found as articles of commerce. It is clearly a contradiction in terms to talk of synergy, when related to a compound preparation of two or more herbs, because the synergy of each is thereby destroyed. The compound complexity of a single herb is such, that it could take a modern research laboratory, years of painstaking analysis to unravel.

A classic example would be the combination of an alkaloid and tannin containing herb, which will precipitate the alkaloid. Such a solution will concentrate the alkaloid at the bottom of the preparation. The danger being that a toxic amount of the alkaloid may be ingested in the final 2 or 3 doses.

The organic acids, such as benzoic, salicylic and tannic acids, can give rise to the precipitation of alkaloids. Undoubtedly, alkaloids and organic acids are to be found together in a herb, and when extracted alkaloidal precipitation does not occur. This is because all the constituents are in chemical equilibrium. However, the addition of further organic acids, by the combination of another herb of similar properties, may be enough to upset the balance and precipitation occurs. Further changes will also occur from a change in the menstruum.

Pharmaceutical Incompatibility 8.26
A pharmaceutical incompatibility exists when a preparation is likely to offend the senses, i.e., taste, touch, sight or smell. For example; a greasy viscous and strong smelling ointment may be found to be offensive. Difficulty may be experienced in persuading a child to ingest a liquid preparation by reason of taste or smell. A preparation may also offend because of color or general appearance. The preparation and dispensing of a medicinal, is an art that the Apothecary should not neglect.

Physical Incompatibility 8.27
A physical incompatibility exists when an attempt is made to combine two immiscible liquids such as oil and water, or in the case of solids; such as camphor and menthol, where a combination of the two produces liquefaction. Precipitation could also be included in this class of incompatibility.

Therapeutic Incompatibility 8.28
A therapeutic incompatibility exists when two or more components of a remedy are antagonistic, e.g. sedative and stimulant. Some substances are especially prone to incompatibility, therefore, combinations of herbs containing them should be avoided, and the preparations of them be prescribed alone, e.g., alkaloids, salicylates and tannins. One of the major mistakes is to combine herbs of the same therapeutic class. This is a sloppy and dangerous procedure.

Solvents used for Herbal Preparations 8.29
The majority of solvents are toxic to a greater or lesser degree. It should also be remembered that it is not possible to remove all traces of a solvent from an extracted substance. There are no perfect solvents, each one has its drawbacks. When considering the suitability of a solvent, it should meet the following criteria;

                                      1. It should display low toxicity to higher life forms.
                                      2. It should not cause the extract to complex or dissociate.
                                      3. It should be preservative in action.
                                      4. It should promote rapid physiologic absorption of the extract.
                                      5. It should be easily evaporated at a low heat.

The following solvents find widespread use in the manufacture of herbal preparations.

                                                                 Ethanol (alcohol).
                                                                 Distilled Water.
                                                                 Aqueous Acetic Acid.
                                                                 Glycerine.
                            Combinations of water, ethanol, glycerine and acetic acid.

In addition orthodox pharmacy makes use of the following;

                                                                Chloroform.
                                                                Ether.
                                                                Light Petroleum.
                                                                Propylene Glycol.

Acetone (dry cleaning fluid) is also used especially with the lactones.

The last 5 of the 10 listed solvents have no role to play in herbal preparations, they are dangerous and unethical, therefore, they will not be further discussed. Of the remaining five solvents, by far the most satisfactory is Ethanol, Water and aqueous solutions of Ethanol, in that they most nearly meet the relevant criteria for the extraction of vegetable drugs.

Solvents and Their General Properties 8.30

Vinegar and Acetic Acid
In lay circles, it is common to use the terms vinegar and acetic acid, as though they are interchangeable. This assumption is incorrect. Vinegar is an aqueous solution that contains acetic acid. There are 5 main types of commercial vinegar.

1. Cider Apple Vinegar, which is made by an alcoholic and subsequent acetous fermentation of apple juice, and contains not less than 4% acetic acid.

2. Glucose Vinegar, which is made by the alcoholic and subsequent acetous fermentation of a solution of glucose, and contains not less than 4% acetic acid.

3. Distilled (Spirit) Vinegar, which is made by the acetous fermentation of dilute distilled alcohol, and contains not less than 4% acetic acid.

4. Malt Vinegar, which is made from an infusion of cereals, or barley malt which has undergone the malting process, i.e., the starch is converted to fermentable sugars by the action of enzymes. The infusion then undergoes alcoholic, and subsequent acetous fermentation, and contains not less than 4% acetic acid.

5. Wine (Grape) Vinegar, which is made by the acetous fermentation of grape wine, and contains not less than 4% acetic acid.

It is quite common when consulting herbals, both ancient and modern, to find the continuing advocacy of vinegar, as a solvent of plant drugs (Acetic tinctures). This convention has nothing to commend it. The solvent powers of vinegar are due to its acetic content. Undoubtedly acetic acid is a good solvent of many substances; its use is restricted to a mere handful of official preparations. This because of the destructive effect of the acids on the bio-structure of the herbal material.

From a medicinal standpoint, vinegar is of use as a local astringent, and internally as a blood cleanser, cider vinegar being a case in point. The chief impurities found in vinegar, possibly due to incorrect manufacturing methods, are copper, tin, lead and sulphuric acid. The essential constituents of vinegar are water and acetic acid, however, different types of vinegar will also contain traces of substances that are derived from the starting liquor. These substances will produce differing physiological effects. Vinegar is prone to putrefaction and decomposition when exposed to air. For those reasons, it has been replaced by dilute acetic acid in all national pharmacopeias.

The acetic acid of commerce, is produced by various industrial processes. The most common being by the destructive distillation of wood, which yields a crude product called Pyroligneous Acid, which when purified, yields the acetic acid of commercial strength.

Description and Physical Properties 8.32
Acetic acid is a clear colorless liquid, with a specific gravity of 1.045 at 25�C. It has a strong vinegary odor and an acidic taste. It produces a strong acid reaction on litmus paper. This strength (38%) of acid, is the one most commonly used by the Apothecary as base material, when producing the official dilutions.

Diluted Acetic Acid (Acidum Aceticum Dilutum 6%), 8.33

Diluted acetic acid is produced to the following formulae;

B.P.V - Acetic Acid 152.6 gm; Distilled Water, sufficient to produce 1000 ml. Mix.

USP X - Acetic Acid 165 gm; Distilled Water 835 gm, to make 1000 gm; Mix them.

The official preparation is approximately 6% acetic acid, in comparison with the 4% of commercial vinegars.

Acetic Acid as Solvent 8.34
Formerly, various dilutions of acetic acid found widespread use as a plant drug solvent, being used as a substitute for alcohol in many preparations. Subsequent analysis of the acetic preparations (Aceta), revealed that plant compounds dissociated in the presence of acetic acid. Many of the products formed were incompatible with other substances and preparations, therefore, its use as a solvent is now restricted to Vinegar of Squill (Acetum Scillae). It is worth noting that Vinegar of Squill is considered to be inferior in its action on the heart and kidneys, in comparison with the alcoholic preparation.

Glycerin C₃H₈O₃, (Glycerol) 8.35  
Glycerin is a trihydric alcohol associated with a small percentage of water. It is a clear, colorless, syrupy liquid with a sweet taste. It has no odor and gives a neutral reaction with litmus.

Glycerin is very hygroscopic (attracts water). It is miscible in alcohol 90% and water, it is insoluble in ether, chloroform and fixed oils. The boiling point is 290�C, however, at that temperature, it usually decomposes, giving rise to acrid fumes of acrolein, which produces intense irritation of the eyes and nasal passage.

Glycerine is manufactured from animal and vegetable oils and fats, by means of a decomposition reaction. The chemical reaction is produced by heat, where the fats and oils are hydrolyzed by means of super heated steam. The fats or oils then decompose into their constituent fatty acids and glycerine.

Glycerine is also obtained as a by product from soap making, where the animal or vegetable fats are decomposed by an alkali such as caustic soda. The fatty acids saponify and separate out as curds of soap, and the glycerine is then recovered from the caustic sludge.

In the human body, fats and oils are decomposed by pancreatic secretions in the small intestine, to yield fatty acids and glycerine.
There appears to be a great deal of misconception about glycerine, its properties and usefulness in therapy.

Commercially three grades of glycerine are recognized;
1. Crude
2. Technical
3. Pharmaceutical or chemically pure *