An In-Depth History of Silver

Prior Civilizations

In ancient times, the first metals discovered and used were gold, copper and silver, in that

order. Among the ashes of fire pits used by Stone Age peoples are the remains of

metallurgical work. Discoverers associated the yellow color of gold with the sun. In turn,

the white brightness of silver became associated with the moon. The Greek word argyros

is derived from a Sanskrit root mean shining white. In Latin, the moon is known as luna.

The surgical cauterizer made from silver nitrate and niter is still known as lunar caustic

today. The later Latin name argentum comes from an Aryan root meaning white and

shining. The word silver is of Gothic origin meaning shiny white. The optical properties

of silver are distinctive because of its exceptionally high reflectivity and very low


For thousands of years, silver has been highly regarded as a versatile healing tool. In

ancient Greece, Rome, Phoenicia and Macedonia, silver was used extensively to control

infections and spoilage. Hippocrates, the “Father of Medicine,” taught that silver healed

wounds and controlled disease. Around 400 B.C., he listed as a singular treatment for

ulcers “the flowers of silver alone, in the finest powder.” Herodotus describes how the

King of Persia carried with him boiled water in silver flagons to prevent sickness. In 69

B.C., silver nitrate was described in the contemporary Roman pharmacopoeia. Pliny the

Elder, in his survey of the world’s knowledge, Natural History (78 A.D.), states in Book

XXXIII, Section XXXV, that the slag of silver “… has healing properties as an ingredient

in plasters, being extremely effective in causing wounds to close up…”

The popularity of medicinal silver especially arose from 702 A.D. through 980 A.D.

throughout the Middle East where it was widely used and esteemed for blood

purification, heart conditions, and controlling halitosis. Paracelsus (circa 1520)

extensively incorporated silver medicinally, and later Caradanus, Pareus and Sala also

used it. Angelus Sala used silver nitrate to successfully treat chorea, tabes dorsalis

(syphilis), and “doubtably epilepsy”. These crude forms of silver were reported by Sala to

rarely cause the bluish hue of skin discoloration due to its overuse (Argyria). It is widely

thought that during the Middle Ages, silver utensils and goblets contributed a bluish hue

to the skin tone of the upper class, resulting in the term “royal blue bloods.” Plausibly the

term “born with a silver spoon in his mouth” was coined during that time for the same

reason, as an attribute for describing the good fortune of health more than having wealth.

These blue bloods were noted to have obtained a measure of protection from the rampant

plagues common to Europe in those centuries. The use of silver to provide bacteria-free

tableware, pacifiers and storage vessels has been practiced throughout history. Today it is

known that metallic silver will dissolve in water to the level of 10-5 g/l, which is toxic to

Escherichia coli and Bacillus typhosus.

Pioneers of the American West would often put a silver dollar into a jar or container of

milk to help keep it fresh without refrigeration. They would also drop silver and copper

coins in their barrels of drinking water to combat bacteria and algae. During the wars

with Napoleon, the armies of Tsar Alexander used water casks lined with silver to clean

drinking water from rivers and streams. This practice by the Imperial Russian army was

common through World War I and continued to be incorporated by some units in the

Soviet Army during World War II.

Raulin recorded the first clinical description of the water-cleansing effect by silver in

1869. He observed that Aspergillus niger could not grow in silver vessels.

Modern Research using the Scientific Method In 1861, Thomas Graham found that

certain solutions would pass through a membrane and others would not. He found a

stable, intermediate state of matter and was able to describe it. Graham discovered that

substances could enter a solution in such a manner that they would exhibit characteristics

quite different from those of a true solution. He applied the term “colloidal” (from kolla =

glue) to this intermediate state, since glue, gelatin, and related substances were the most

obvious to him as being in this unique state.

The Swiss botanist von Nageli recorded one of the amazing discoveries of the 19th

Century in 1869. Von Nageli coined the term “oligodynamic” to describe the

microbiocidal properties of a metal hydrosol (e.g. copper, silver and tin) at minute

concentrations. Silver is unique in its action against micro-organisms.

Recent studies confirm that silver ions are active against bacteria at concentrations as low

as one part per billion in pure water. Silver ions react rapidly with the walls of

prokaryotic cells typical of micro -organisms, whereas the membranes of eukaryotic cells

of mammals strongly resist any effect by silver.

In 1884, the German obstetrician C.S.F. Crede, observed that there was a 79%

relationship between blind children and maternal venereal disease. He subsequently

introduced a prophylactic l% silver nitrate eye solution for newborns for the prevention

of ophthalmia neonatorum. Following its introduction, the incidence of eye disease in

newborns dropped to about 0.2%. His treatment was a milestone in clinical prophylaxis

and became a government regulation throughout most of the world. By 1897, silver

nitrate began to be used in America to prevent blindness in newborns and is still used

today. By 1910, Henry Crookes had documented that certain metals, when in a colloidal

state, had strong germicidal action, but were harmless to human beings. The

oligodynamic concept motivated the development of many antimicrobial processes and


One of the water purification developments that took place in 1928 was the development

of Katadyn silver, described as a porous metallic, spongy mesh that attempts to maximize

surface area. This silver meshwork also contains a small quantity of gold or palladium.

Katadyn silver has been used inside flasks and storage containers and with water filters.

Both the U.S. and Russian space shuttle vehicles use electrified silver and copper water

filtration systems.

Many urologic implements were made of silver and commonly used during the period of

1930 to 1960. This author has a Keyes-Ultzman silver urethral canula designed to reach

the prostatic urethra. The advent of inexpensive stainless steel and improved sterilization

methods greatly diminished the clinical market for silver implements.

During World War II, Charles L. Fox, a surgeon, observed that many soldiers died of

uncontrolled bacterial infection in open wounds. He had long used silver nitrate as part of

his medical practice, but it was far too aggressive with protein structures – limiting its

clinical uses. His research at the Department of Surgery and Microbiology, College of

Physicians and Surgeons, Columbia University, New York, led to the discovery of silver

sulfadiazine. This combination provided controlled release of silver ions in a wound

along with an active antibiotic drug. Silver sulfadiazine provided a steady, long-term

delivery of silver ions onto or into a wound. This combination remains a medical

milestone in the treatment of burn wounds and is the standard against which all other

burn wound treatments are measured. It is a dual antagonist: silver has the primary

activity against pathogens but should an organism be sensitive to sulfonamids, the

sulfadiazine component will also be active. This dual function has been extensively

studied to show effectiveness against a wide range of bacteria, fungi, extracellular viruses

and protozoa.

During the last century, advances in pharmacological manufacturing methods sought to

harness this time-valued strategy expressed in nearly all silver formulations. Yet early

manufacturing methods rarely created high quality, homogeneous oligodynamic silver.

Nevertheless, more than 96 different silver medicinals (many used intravenously) were in

use prior to 1939, as documented by the Council on Pharmacy and Chemistry of the

American Medical Association. The introduction of Argyrol, a silver-protein compound

that provided silver ions for minor illnesses, was one of the most successful silver-based

preparations. Argyrol was widely marketed until the advent of the miracle drugs during

the 1950′s.

Also during the 1950′s, Czech researchers developed a gennicidal silver product called

“Movidyn”. It was initially popular because it was much less expensive than chlorinebased

disinfectants. Studies of contaminated wells found that Movidyn completely

eliminated anaerobic bacteria such as Vibrio cholerae, which causes cholera, and aerobic

bacteria such as Escherichia coli, a potential enteric pathogen and the most common

organism associated with “traveler’s diarrhea”, and the Rickettsial pathogens associated

with typhus, and protozoa such as Entamoeba histolytica associated with amebiasis.

Apparently the Soviet military had the Czech manufacturing facility disassembled and

shipped to Russia.

Charles E. Renn at the Department of Sanitary Engineering and Water Resources, Johns

Hopkins University conducted studies in the 1950′s that revealed drinking water could be

disinfected if very fine silver particles were deposited in an activated carbon. The

resulting filter acted as a mild galvanic couple or battery that caused silver to dissolve.

Silver concentrations varied 25 to 40 parts per billion. The activated carbon adsorbed

undesirable organic compounds including cancer-inducing trihalomethanes that can be

generated in the presence of chlorine. Silver impregnated activated carbon is a major

component of the $4,000,000,000.00 U.S. water purification market.

Research conducted at the Department of Microbiology and Immunology, University of

Arizona proved that silver and copper ions effectively eliminate Legionella in drinking

water pipelines. Silver and copper ions penetrate biofilms that build up in hospital

plumbing, destroying entrenched Legionella and other pathogenic organisms. The

stability of silver and copper ions provides long-term margins of safety. In addition, these

ions drift into and sanitize the less-used portions of the water supply system. Over 100

hospitals in the U.S., Canada, and U.K. have silver-copper ionization systems to eradicate

Legionella pneumophilia from hot and cold water recirculation pipelines.

Studies conducted over decades at the College of Physicians and Surgeons, Columbia

University revealed that the minimum bactericidal concentration of silver required for

biocidal activity against bacteria in pure water was 0.5 and 0.1 um/ml or 0.1 ppb.

A project begun in the early 1970′s by Robert Becker, an orthopedic surgeon, involved a

silver nylon product. This project was instigated in order to find an electromagnetic

shield. Instead, it lead to the revolutionary discoveries by Becker of silver’s unique

properties to increase the rate of tissue regeneration in diseased or damaged tissues and

his discovery that silver ions could induce fibrocytes to dedifferentiate into stem cells and

back again. Becker also addressed the fact that children under 4 years of age could

regenerate fingertips with silver. His extensive studies suggest that the regeneration effect

initiated by silver appears to be similar to that seen in salamanders, which regenerate lost


While at the Upstate Medical Center, University of Syracuse, Syracuse, New York,

Becker developed a technique that released large quantities of silver ions from silver

electrodes via small electric currents of approximately 0.9 volts. Electrically driven silver

ions were found to consistently penetrate one centimeter within 20 minutes into local

proteins at a wound site and were effective in treating osteomyelitis, similar infectious

diseases, and the silver proved to be a stimulus for reconstruction of tissue in large


Decades of practical application revealed that this technique was effective against both

gram-negative and gram-positive bacteria. No bacteria proved resistant to the silver ions

or developed a resistance to silver after treatment. Toxic effects to this process were

negligible. During electrically driven silver ion treatment, a profuse exudate composed of

large numbers of cells formed at the wound site. This exudate was accompanied by a

dramatic increase in the rate of wound healing. No other known technique is capable of

producing this effect.

One of Becker’s research associates, A. Bart Flick, continued work in this area for

professional and commercial applications. As a result, Flick has filed patents in 1994,

1996 and 2000 for silver-based wound dressings that are far superior to anything that has

ever been available before. He has also obtained approval for these wound-dressing

products from the U.S.

45 Food and Drug Administration.”" Because of the success of these silver dressings,

many other medical product manufacturers have filed for their own parallel products.

Silver products include many variations of bandages, intratracheal tubes and catheters.

A 12 month randomized, multicenter trial study of uncoated and silver-coated urinary

catheters was conducted in wards at the University of Medicine, Baltimore, the

University of Virginia Health System, Charlottesville and the University of Pittsburgh

Hospital, Pittsburgh. This trial revealed that the risk of infection declined by 32% among

patients in whom silver coated catheters were used. The silver subset of patients also had

a decreased length of hospital stay and a decrease in morbidity. The estimated savings in

hospital cost was nearly $500,000.

In the early 1970′s treatment of severe burn cases using silver topical salves, such as

silver sulfadiazine, provided superior control and prophylaxis. Today, multiple drug

resistant (MDR) microbes are challenging this formulation’s effectiveness, but this review

shall discuss how state-of-the-art silver protocols and formulations offer superior

protection against microbial strategies for acquiring resistance.

Absolute microbial resistance to medicinal silver has not been scientifically established.

Several studies have indicated that some bacterial species have physiological mechanisms

that circumnavigate silver’s toxicity. Although it is clear that some pathogens have

mechanisms to survive exposure to certain forms of silver, these mechanisms are limited

when compared to higher life forms. Herein lie all the clues necessary to identify

strategic silver therapeusis that pathogens are unlikely to survive.

It is probable that pathogens lack sufficient defense mechanisms to circumvent the toxic

effects of silver ions when oligodynamic silver is delivered in sufficient, physiologically

compatible quantities. In fact, the “apparent” resistance of microbes to silver was

mistakenly noted by many who failed to notice and identify: (a) insufficient

oligodynamic silver particle concentrations, (b) ineffective percentages of charged

particles, (c) inadequate protocols or (d) improper procedures. Reports that multipledrug-

resistant (MDR) pathogens (i.e., MRSA ( and Acinetobacter spp.) were truly

resistant to silver proved to be erroneous. Grier stated, “Some so-called silver-resistant

micro-organisms may result from an apparent neutralization of the metal’s inhibitory

action or other assay artifacts. These include the presence of chelators such as serial

amino acids, constituents of hard water, different buffers, light, incubation temperature,

and particularly, soluble components of trypticase soy agar (TSA) and tryptose glucose

extract agar (TGE). Currently, bacterial pathogens are unable to cope with sustained

exposure to a silver hydrosol.

With the advent of antibiotic therapy, medicinal silver products fell largely into disuse

(circa 1940 -1945), with the notable exceptions of topical silver salves and neonatal eye

drop preparations. These salves advanced the science of “silver salt-derived” delivery and

effectiveness in the mid 1960′s. Then, during the mid 1970′s, several papers were

published that utilized electrically activated silver probes as delivery systems for targeted

oligodynamic. More information is available from the U.S. FDA on Silverlon or the

company that manufactures this dressing product. silver strategies. 81 The interest in such

strategies continues to grow to the present, with high efficacy being obtained for viral

vectors such as HIV 82 and resistant bone and dental infection.

83 Sufficient defense capacity to mitigate morbidity clearly exists in higher organisms,

including humans (with the exception of medically benign Argyria).g4 Zhao and Stevens

state that, “With the rise of antibiotic-resistant bacteria, silver is re-emerging as a modern

medicine because all pathogenic organisms have failed to develop an immunity to it


Silver is being used in the U.S. as a broad-spectrum antiseptic in several commercial

arenas. For example, silver dihydrogen citrate, Axenohl° is an electrolytically generated

compound that works well with other compounds used as hard surface disinfectants for

food contact surfaces, clinical work surfaces, medical disinfectant wipes, and water

treatment systems. The black polyvalent silver oxide [Ag404] is a compound unit with

two single-charged and two triple¬charged silver atoms. It is a microcidal compound

effective against bacteria, yeast and mold. It is a safe, EPA approved antiseptic oxide

compound. Tetrasil° is an example of this oxide used in a bactericidal topical ointment. It

is also the best choice of relatively inexpensive silver currently available for sanitizing

acrylic hot tubs.

Research initiated in the 1990′s by the Chinese government through the Department of

Materials Science and Engineering, Tsinghua University, Beijing, studied the reaction

between bacteria and silver ions. Their goal was to develop an effective antiseptic that

would sanitize almost any surface. They developed a silver/zircon phosphate complex

that proved to be an excellent disinfectant with stable, long-term sterilization effects. This

silver complex also maintained perfect safety with no toxicity to humans. The Science

and Technology Ministry of China certified the new antimicrobial as a “National Key

New Product”. It is marketed as Concal PAg-40TM.

In Vitro Studies

The medical literature of the early 20th century regarding silver provides an important

cautionary lesson from the past. Previous scientists, who were either supporters or

detractors of silver medicinals, typically expressed equivocal knowledge and misapplied

context because they failed to recognize silver speciation. This fault undermined their

definitive knowledge about silver. Correct and in-context discernment of silver’s

therapeutic threshold remains elusive to most investigators even today. This “box”

perception about silver will continue to lose its limitations as technology continues to

prove itself outside of that box in the coming decades.

Clinical reports on silver medicinals began to flood into the various medical journals

worldwide at the start of the last century. Initially, the Journal of the American Medical

Association took a negative position. But within 11 years, a true revolution in medical

practice with silver medicinals occurred that did not subside until the U.S. government’s

purchase of the patent rights to penicillin (circa 1940). Throughout this period, 1920

through 1942, JAMA articles were replete with oral (per os) and intravenous clinical

reports of the efficacy and side effects of silver medicinals. 86 In tandem with research in

America, Great Britain published prominently in such respected journals as The Lancet

and the British Medical Journal.

Perhaps the first definitive attempt to comprehensively evaluate the efficacy and variety

of silver medicinals was published by the Department of Pharmacology of the Medical

School of Western Reserve University, Cleveland, circa 1923. In terms of efficacy, this

landmark study arguably established “silver nitrate” as the benchmark for all silver

medicinals. Unfortunately, the excitement this study produced simultaneously placed at

risk subgroups of patients susceptible to symptoms of argyria. Had the technology then

existed to create vast surface areas with “pure hydrosols of oligodynamic Ag +” not only

would such products have revealed their greater potency over that of silver nitrate; but

also, argyric thresholds would have been nearly impossible to attain during any course of

therapy. Oligodynamic (picoscale) surface area enables maximal exposure of silver

particles in the least amount of volume, thus achieving potency several orders of

magnitude over suspensions of much higher ppm- silver speciations (which necessarily

manifest inferior surface area exposures). In other words, technology today can produce

smaller quantities of silver that are vastly more potent than was ever historically possible.

The result is a dramatic elucidation of the Therapeutic Index, resulting in unprecedented

safety, efficacy, and dimension to protocol parameters.

For example, beginning in 1970 at the University of Wisconsin, under contract from

NASA to determine the biocidal effects of silver, researchers were able to determine that

lethal effects of silver ions could be reliably reproduced at concentrations of only 250-

ppb when exposed to infectious agents over two hours or less in vitro. These researchers

even found that even 50-ppb over four hours or less achieved a significant biocidal effect.

The University study with laboratory-produced silver ions worked extremely well,

although the extinction times were long. Follow-on investigations of these early silver

medicinals failed to exert adequate lethal effects upon antibiotic resistant infectious

organisms. However, as technology advanced, these highly resistant organisms were

again found to succumb to the lethal effects of new silver medicinals. Additionally,

extinction times proved to be dramatically lessening.

In Vivo Studies

At the height of its popularity (from 1900 through 1940), a fair estimate of humans given

intravenous silver medicinals worldwide exceeded several million. The shear scale of its

utilization defined and confirmed silver medicinals as effective anti-microbials.

During my training as a medical student, I had an opportunity to witness several of my

elder attending physicians using various silver formulas in their clinical practice. It was

fascinating to me that silver medicinals were widely used by one generation of clinicians,

yet this therapeutic approach simply ended by my generation. Why? In terms of safety

and efficacy, was there a justification for abandonment of this approach?

One recent and noteworthy in vivo study published in the Journal of Clinical Ultrasound

(2000) reported on a protocol involving puncture, aspiration, injection, and re-aspiration

(PAIR) with silver nitrate directly into hepatic hydatid cysts with beneficial long-term

results. Other preliminary evidence in vivo suggests that both hepatitis-C virus (HCV)

and HIV , and other viral vectors, as well as in vitro studies on herpes, and the worst

bacterial scourges (i.e., antibiotic resistant disease vectors) may become events of the

past via the judicious and strategic use of a state-of-the-art silver medicinal and delivery

system. , , , , , , ,

Antimicrobial coatings for the inside and outside of medical catheters using silver have

been developed for latex, polyurethane and Teflon devices. These silver coatings are very

effective at blocking bacteria, such as E coli and S aureus, from entering the body along a

catheter pathway. , ,


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