The History of Saltpeter - V

In today's post, we will look at the early history of saltpeter production in the US.

When the early colonists from England arrived in the US in 1620 and established a colony in Plymouth, Massachusetts, they brought supplies of gunpowder from Europe. However, as the Massachusetts Bay Colony began to grow, it became necessary for the settlers to start manufacturing their own gunpowder locally, because they could not depend on supply ships reliably coming across the ocean from England.

Since there were no known deposits of natural saltpeter in the area, the settlers began to make saltpeter plantations, using the same techniques that were in use in England. The first reference to saltpeter manufacture comes from an order of the General Court of Massachusetts, dating from June 6th, 1639, where it granted 500 acres of land at Pecoit to one Edward Rawson, "so as he goes on with the powder if the saltpeter comes." By 1640, a saltpeter house was operational in Boston. By 1642, the General Court of Massachusetts  passed an order to promote public safety "by raising and producing such materials amongst us, as will perfect the making of gunpowder, the instrumental means that all nations lay hold on for their preservation etc., that every plantation within this colony shall erect a house in length 20 or 30 foote, and 20 foote wide within one-half year next coming, &c., to make saltpeter."

In 1666, we see two more orders passed in the General Court of Massachusetts. The first dating from May 23rd states, "whereas, there is necessity of having supply of gunpowder in this jurisdiction, and forasmuch as Sergt. Richard Wooddey, of Boston, in the county of Suffolk, and Mr. Henry Russell, of Ipswich, in the county of Essex, have been and are upon the work, and in preparation for saltpeter, for their future encouragement, or any other that shall appear to attend the promoting thereof, this Court doth declare and order that the said Richard Wooddey and Henry Russell are impowered to go on and proceed in the said work." It then grants them special permissions to build their business. The second order from October 10th states that "whereas the Court hath encouraged and authorized some persons to make gunpowder, and have promised to enable them thereunto by such public and necessary orders as may conduce to the effecting of the same, the consideration whereof hath moved the Court hereby to order and enact, that the selectmen of every town (where the powdermakers authorized by this Court shall desire it) be authorized and required hereby to make and execute such orders in their respective towns as they shall judge meet, with the advice of skilful men, for increasing and procuring of saltpetre, and to impose such penalties as the selectmen shall deem meet, not exceeding ten shillings for one offence, upon all persons that shall neglect or refuse to perform such order or orders for the propagating and increasing of saltpeter in their respective towns; and moreover, the said selectmen are further impowered to choose and appoint an officer or officers, and to allow him a convenient stipend annually for his pains out of the fines or otherwise, to look to the executing such orders as they shall make in their behalf."

The next big event we see is from 1675, when a powder mill was built in Milton, Massachusetts. It was water powered and built near the Neponset river. In August 1675, Governer Leverett wrote to this friend and revealed, "We are upon a work for making powder and have erected a mill in order thereunto at Neponset, about six miles from Boston. Our difficulty will be for peter, which we must, in our beginning, have from without us, but hope, in time, may raise it amongst us." The last sentence shows that the sources of saltpeter for this mill were still uncertain at this point.

Interestingly, as the colonies developed, Great Britain started to produce gunpowder based on cheap saltpeter imports from India (we will study that trade soon). Therefore, it actually became cheaper for Americans to import their gunpowder from England and this led to many powder mills in America closing down. Then, when the American revolution started, there was only one gunpowder mill in America, the Frankford Powder Mill, built by Oswald Eve in Frankford, Pennsylvania. However, this mill was pretty small and could only supply the American forces with small amounts of gunpowder. It was recorded that Oswald Eve signed a contract on January 11th 1776, with the Continental Congress, to supply gunpowder at $8 per hundredweight. In order to ensure that his was not the only mill to make gunpowder, Congress approved the construction of the Continental Powder Mill on February 16th 1776, on French Creek, eight miles from Valley Forge, based on the techniques learnt from inspecting Eve's mill. As it happens, Congress wasn't entirely certain about Eve's patriotism and suspected that he was dealing with the British as well. Therefore, eight other mills operated by other private businessmen were also contracted to supply additional materials. Eve's mill was later seized by the British forces in September 1777, when they captured Philadelphia. Eve was subsequently accused of treason by Congress for trading with the British and had to flee the US.

It must be noted that the new powder mills could not supply the needs of the Americans, because they couldn't obtain enough saltpeter. Desperate for gunpowder, American forces tried to get it by capturing supplies from the British. Both George Washington and Congress ran separate operations to raid a British magazine on the island of Bermuda. When the situation was very dire, help came from the other European nations. Dutch merchants were already trading with American ships and then, the French got into the act. The French had built up their saltpeter plantations with the help of gifted chemists such as Antoine Lavoisier (the father of modern chemistry) and they had plenty of supplies of saltpeter and gunpowder. The French were able to supply enough to meet the needs of America. In fact, if it wasn't for French supplies of gunpowder, American forces would never have been able to continue the war of independence.

The importance of being self-reliant on gunpowder was not lost on America's founding fathers and therefore, efforts were made to build up supplies after the American revolution. American ships began to import raw saltpeter from India, but the quality of gunpowder produced was not very good. Then, in 1800, a rich Frenchman named Éleuthère Irénée du Pont escaped with his family from the French revolution and came to America.

Éleuthère Irénée du Pont

Before he came to America, the young du Pont had studied for some years under the famous chemist, Antoine Lavoisier, who was a friend of his father. He had also worked in the Regie des poudres, the French government agency responsible for manufacturing gunpowder. From Lavoisier, he learned the latest techniques in manufacturing nitrates. Later on, he gave up his chemistry career and began to help his father run a publishing house. Then the French revolution happened and he and his father were arrested and nearly executed. They decided to flee France with their families and come to America. Meanwhile, his former mentor, Antoine Lavoisier, was not so lucky and was executed by guillotine during the French revolution.

When Du Pont first came to America in 1800, he didn't actually want to go into the gunpowder manufacturing business. As it happened, the quality of gunpowder manufacturing in the US was very bad. The story goes that Du Pont went hunting with a certain Major Louis de Tosard, who was a former French artillery officer who had also escaped from the French Revolution and was employed by the US army to buy gunpowder supplies. During the hunting trip, Du Pont's gun misfired and he commented that despite the high price of gunpowder in the US, it was of very poor quality. That's when he thought about his earlier career in making gunpowder in France. He arranged with Tousard to tour American gunpowder factories and came to the conclusion: "There already exist in the United States, two or three mills, which make very bad powder and which do however a very good business. They use saltpeter from India, which is infinitely better than that which is produced in France, but they refine it badly."

Du Pont decided that he could use his experience from France to better refine the saltpeter and thereby produce higher quality gunpowder. With his father's support, he began to raise capital in France to build a new factory in America and also arranged to import machinery from France. The new E.I. du Pont de Nemours and Company gunpowder mill was established in 1802 on the Brandywine Creek in Delaware. Initially, the mill was just a saltpeter refining factory, but they soon moved into manufacturing gunpowder as well. Within a few years, his company became the largest gunpowder manufacturer in the United States and the Federal government became one of his biggest customers. The company he founded would go on to become one of the largest and most successful American corporations in history and is currently the world's fourth largest chemical company.

Other American companies that were founded after Du Pont include the Hazard Powder Company (founded 1832), the Oriental Powder Company and the Laflin Powder Company (the last two being owned by members of the Laflin family, who had a history of making gunpowder since the American revolution). By the time of the Civil war, these four companies were supplying most of the gunpowder to the Union side.

In our next post, we will study how saltpeter was manufactured by the Confederate forces, during the Civil war.

The History of Saltpeter - IV

In our last couple of posts, we saw the basics of saltpeter extraction and also an insight into the bacterial and chemical processes involved. As we saw previously, it was the job of saltpeter men to go around the country and locate soils rich in nitrates, so that saltpeter could be extracted from them. They often found these lands close to places where organic materials decomposed, which were sheltered from rain and sun. This usually meant digging in cellars and stables of various farms. However, the formation of saltpeter in these areas was a slow process and the supplies could not keep up with the demand. Therefore, people began to prepare special areas to produce saltpeter. These areas were called niter beds (or nitre beds, if you're used to British spelling). Other names for these include nitraries and saltpeter plantations. We will study how these worked in today's post.

Niter Beds. Click on the image to enlarge. Public domain image from a woodcut from 1598.

Workers would prepare long trenches lined with clay and pile on heaps of manure, rotting leaves, plants and urine, arranged with layers of limestone and ash in between, and small twigs, branches and straws in the middle, to give the mixture sufficient porosity. Such heaps can be seen as C in the image above. The sides of the various heaps protect each other to some degree from wind and weather. Every week, the workers would keep the heaps moist by adding more urine, dung water, water from drains etc. The idea was to keep the heaps moist, but not too wet. Urine from drinkers of beer and wine were in much demand, as it was thought that this resulted in superior quality of saltpeter. The process needed to be somewhat carefully controlled because if it was overdone, the production rate of saltpeter would actually decrease.

Meanwhile, the workers would collect pure rainwater in a large vat (A in the image above), as it is a relatively pure source of water without any minerals dissolved in it. They would also collect wood (D in the image) to be used to prepare ashes and for boiling the liquids later on. After about a year, the heaps would be ripened enough and a saltpeter digger (E in the image above) would dig into them and take them into buildings B and A for processing.

Click on the image to enlarge. Public domain image.

Inside, they would use the pure rainwater to dissolve and leach the saltpeter crystals from the compost heap and then use the wood to boil the water and extract the crystals from it, as described in the posts previously.

As can be imagined, running a nitrary (saltpeter plantation) meant that the smell was very nauseating. In fact, one of the major qualifications to be a nitrary manager or worker was to be able to tolerate the incredible stench produced. That's why many of these operations were located out in the countryside, away from most people.

The remains of what once used to be the largest nitrary in Dijon, France. This was originally out in the countryside, but is now a residential neighborhood of the city. The only hint of what used to be here is the street sign. In the inset, it says "Rue de la Raffinerie" (i.e.) "Street of the [saltpeter] refinery."

Click on the image to enlarge.

These nitraries were dedicated to producing saltpeter and some countries (e.g. France, Sweden, Germany, colonial-era America etc.) introduced laws requiring people to set aside X amount of land in each village for niter beds. A well run operation could produce, every two years, about 2-4.5 kg. (about 5 to 10 pounds) of saltpeter per cubic meter of dirt. It was a slow, painstaking, dirty and labor-intensive job, but for several countries, it was necessary for their survival.

In our next post, we will look into the works of a certain Professor Joseph Leconte, who wrote a pamphlet on the production of saltpeter during the Civil war.

The History of Saltpeter - III

In our last post, we studied one of the techniques of producing saltpeter. We did promise there that we will study another method using niter beds. But, before we dive into that topic, let's cover a few more things that were left out in our previous post.

First, in case the reader is wondering, it is not possible to simply pick up a pile of fresh dung and urine and manufacture saltpeter that way. The dung and urine need to ferment for a while (at least 6 months or more), with sufficient moisture and shelter from rain and sun, and the soil needs to be alkaline and have certain compounds and not grow any crops on it.

Since we have the benefit of modern chemistry and biology knowledge, let us try to understand what is actually happening. First, when animals and people produce a large amount of urine and dung, under the right conditions, certain bacteria will turn the urea into ammonia and then combine that ammonia with oxygen in the air to produce nitrate ions. Now, these nitrate ions are looking to combine with other minerals. If the soil contains minerals such as calcium carbonate (limestone), magnesium carbonate or potassium carbonate, these minerals with react with the nitrate ions being produced by the bacteria, to form calcium nitrate, magnesium nitrate, potassium nitrate etc. Now if plants are allowed to start growing here, they will absorb the nitrates and grow tall and green, but there will be no saltpeter produced, since the plants use up the nitrates in the soil (nitrate compounds have been used as fertilizer for this reason). However, in stables, the animals will eat any plants and therefore, the nitrates can continue to form under the floorboards and walls of adjacent buildings. Similarly, if the ground is porous and dry, plants won't grow well and therefore nitrate crystals can form on it.

Now remember that we said that nitrates such as calcium nitrate, magnesium nitrate, potassium nitrate etc. are formed. Of these, only potassium nitrate is useful to us for gunpowder. The other two nitrates absorb too much water from the air and this reduces their explosive strength. The trick is to separate the potassium nitrate from the others. An Arab scientist from Syria named Hassan Al-Rammah described how to do so, in his book from 1270 AD titled "al-Furusiyya wa al-Manasib al-Harbiyya" (i.e. "The Book of Military Horsemanship and Ingenious War Devices"!) The details in his book seem to indicate that the method is of Chinese or Indian origin. The method described consists of dissolving all the nitrates in water and mixing in a lot of wood ash (which contains a lot of potassium in the form of potassium carbonate). The potassium ions in the wood ash replace the calcium and magnesium ions in calcium nitrate and magnesium nitrate and leave behind potassium nitrate, which can be crystallized. The knowledge of this method went westwards via the Italians and spread to the rest of Europe. A version of this method was described in the previous post.

All of this seems very obvious to us readers, who have had the benefit of knowledge passed to us by hundreds of scientists and inventors over many centuries. However, for people living in the 13th to 18th centuries, who did not have the knowledge of chemistry and biology that we do, the formation of saltpeter crystals was practically magic. They understood that decomposition of organic matter might have something to do with it, but they could not explain why saltpeter crystals would form under stables and cellars, but not in the open fields where dung is also found, and also why saltpeter crystals would not always form under stables if the weather conditions weren't right (the role of certain types of bacteria in the nitration process wasn't fully understood until the late 19th and early 20th century). The source of dung also had an effect on whether saltpeter was produced or not. While it was known that seabird guano was good for fertilizer, it wasn't as good for saltpeter production. However, some soil found under dove cotes (i.e. houses for pigeons and doves) was found pretty rich in nitrates. Stables provided with porous floors, such as straw and ashes, allow the formation of saltpeter. Some caves with limestone floors and filled with bats, would provide good saltpeter from the bat guano piles which were centuries old. Another puzzle was why sunlight and rain affected the production of saltpeter. Again, they didn't fully understand the roles of bacteria, soil chemistry, other minerals etc. This is why the role of the saltpeter men in various countries became so important, because people couldn't guarantee that saltpeter crystals would form at any particular location and it was left to saltpeter men to sniff around and find rich deposits of saltpeter. Since it was such a vital ingredient of gunpowder, they were given permission by their country's rulers to dig literally anywhere and given state protection from angry landowners.

In our next post, we will start looking into niter beds.

The History of Saltpeter - II

In our last post, we studied the components of gunpowder and noted that the key one was potassium nitrate, whose source was from saltpeter. As we noted earlier, the other components of gunpowder were relatively easy to obtain, but this one was not. We will study the history of saltpeter production in this post.

In the fifteenth and sixteenth centuries in Europe, saltpeter's purpose was well understood in the manufacture of gunpowder, but its sources were not. People were not too sure if it could be mined as a mineral or grown in a field like crops. As late as the 1770s, one noted chemistry lecturer admitted that 'we are much in the dark as to the origin and generation of saltpeter', although he knew that it was to be found around 'earth and stones that have been impregnated with animal or vegetable juices susceptible of putrefaction, and have long been exposed to the air... It is a product of elements, deposited in the bosom of the earth... and may not improperly be called the universal and unspecific mercury.' As saltpeter is found as an efflorescence on the surface of the earth, it was assumed by many chemists that it was of aerial origin. In 1821, John Davy, the brother of noted chemist, Sir Humphry Davy, after examining some niter-yielding caverns of Sri Lanka, concluded that it was formed from the nitrogen and oxygen in the air. Around 1890 is when the role of bacteria in the nitrification process was understood. In fact, the full process of nitrification was not understood until the twentieth century.

In some parts of the world blessed with the optimum weather conditions and soil chemistry, saltpeter could be mined right off the ground. However, there are few places in the world with this correct mix of factors: parts of Northern India, Egypt, Spain and the Atacama desert in South America are some of the well known ones. Northern India, in particular, was well known for its saltpeter trade and this was exported to the middle east in the thirteenth and fourteenth centuries, and from then on, to Europe. However, others had discovered artificial methods of making saltpeter as well and these came to European notice as well. We will study the artificial methods of making saltpeter first.

The technology of making saltpeter by artificial means seems to have been invented in Asia and spread westwards into Europe. As might be expected, the Italian states, especially Venice, with their trading interests with the Turkish empire and the middle east, were the first Europeans to gain the knowledge from Asia, of how to produce saltpeter by artificial means. The metallurgist, Vannoccio Biringuccio, from Siena, wrote a well-known book on metalworking, De La Pirotechnia, which was published in 1540, shortly after his death. In this book, along with dealing with metals and alloys, there are notes devoted to saltpeter production. It is known that Biringuccio had a monopoly on saltpeter production in Siena around 1524, so he must have had knowledge of the process before then. This book was copied by several authors and eventually translated into English, and this is how the knowledge of the process gradually spread northwards in Europe.

In most of Europe, and England in particular, they were initially content to simply purchase the ingredients and finished gunpowder from other sources. In particular, trading with the Mediterranean countries for sulfur, saltpeter and gunpowder and northern European countries for saltpeter and gunpowder. Northern Europe was preferred as a source of gunpowder because the commodities were strategically located for military operation on the European continent.

England's need for gunpowder accelerated under King Henry VIII. When he invaded France in 1513, his army carried 510 tons of gunpowder with them, but the siege guns consumed 32 tons of powder a day. Very soon, he was importing gunpowder from other European countries. He commissioned a German named Hans Wolf to travel 'from shire to shire, to find a place where there is stuff to make saltpeter of.' His successor, Queen Elizabeth I, faced the Spanish Armada, and caused the demand for gunpowder to go even higher. She granted a Dutchman, one Gerard Honrick, the sum of 300 pounds, to teach her subjects the art of saltpeter making. His rules:

1. Black earth, the richer the better. The color shows the rich organic decomposition.
2. Urine - especially from those that drank wine of strong beer
3. Dung - especially from horses fed with oats
4. Lime made from oyster shells or plaster of Paris

The moistened ingredients were to be layered in beds to which ashes were added (ashes from oak leaves being recommended) and the resulting salts were to be leached out and boiled to form the crystals of saltpeter.

The following instructions come from a book called De re Metallica (it means, On the Nature of Metals in Latin), written by Georg Bauer, better known by his pen name of Georgius Agricola. It was published in 1556 and undoubtedly influenced by the above mentioned De la Pirotechnia. This was an influential book in the fields of chemistry and mining and remained an authoritative text on mining for 180 years after its publication. There is a chapter on saltpeter extraction, which we will describe below:

Click on the image to enlarge. Public domain image.

A - Reduction Pan, B - Large Vat, C - Plug, D- Tub, E - Crystallization vat.

Saltpeter diggers would dig up soil found near stables or dovecotes, where there was a strong concentration of dung. The best saltpeter came from a dry, slightly fatty earth, which if retained for a while in the mouth, has an acrid or salty taste. Then, they would take a large vat, (B in the figure above), and fill it with layers of this soil and a powder in layers of a palm deep. The powder consists of two parts of unslaked lime and three parts of ashes of oak, holmoak, Italian oak or Turkish oak or some such suitable material. Alternate layers of soil and powder are filled in the large vat, to about three quarters of a foot from the top. Then water is added until the vat becomes full. As the water seeps into the material, it dissolves the saltpeter. Then the plug (C in the figure above) is pulled and the solution is drained into smaller tubs (D in the figure above). The solution is then poured into a caldron or reduction pan (A in the figure above), which is a flat shallow pan made of copper, which is placed on top of a fire. Here, the solution is boiled for several hours until about half of the water evaporates, and the solution is allowed to settle down. Any impurities in the solution form a dirty scum on top, which is then removed. Then it is boiled again and lye and rock alum are added to remove any further impurities and it is boiled again leaving behind a concentrated solution of saltpeter liquor. Then the concentrated solution is transferred to crystallization vats (E in the figure above). These vats have copper rods that act as nucleation sites for crystals of saltpeter to form on them. After three of four days, the rods are removed and the saltpeter crystals scraped off them. The solution left behind in the vats is partially used to wash the crystals after they are scraped off, and the rest of it is reboiled to concentrate the solution even more. The washed saltpeter crystals are placed on boards to drain and dry up.

Of course, as the demand for gunpowder and hence, saltpeter, went up due to the numerous wars in Europe, stables and dovecotes didn't provide enough saltpeter. The next solution was niter beds, which we will study in our next post. 

The History of Saltpeter - I

In our last post, we looked into the specialized profession of Saltpeter Men. Which brings us to another important topic of study, to which we will devote a few posts: the history of production of saltpeter (spelled "saltpetre", if you spell things British-style), especially in Europe and America.

As we studied a while ago, the first propellant used in firearms was black powder, otherwise called gunpowder. This was what was used from the 13th century to the 19th century. When we studied the chemistry of black powder a while ago, it was mentioned that the three main components of gunpowder are:

1. Saltpeter
2. Charcoal
3. Sulfur (or Sulphur, in British spelling)

Chemically speaking, the three components are really Potassium Nitrate (from the saltpeter), Carbon (from the charcoal) and Sulfur. Early gunpowder makers used different ratios of these three components to produce gunpowder. For instance, the Germans used a ratio of 4 parts of saltpeter, 1 part of charcoal and 1 part of sulfur by weight in the 1500s. The English used the ratio of 6 parts of saltpeter, 2 parts of charcoal and 1 part of sulfur during the battles of Crecy and Agincourt. By the 1750s or so, almost everyone had settled on the ratio of 15 parts of saltpeter, 3 parts of charcoal and 2 parts of sulfur, and this ratio had continued to modern times as well.

Of the three components, charcoal was well known to practically every one in every region of the world, in the 13th century. 

Pieces of charcoal

Charcoal has a long history, from thousands of years ago. Prehistoric drawings made in caves have been chemically analyzed and determined to be made by charcoal sticks. By the Bronze age, people were using charcoal to make fires hot enough to melt copper and later on, iron as well (ordinary wood fires cannot get hot enough to do this, but charcoal fires can). So, by the time of the 13th century, charcoal was known to everyone in the world. In fact, charcoal manufacturing was even a profession and last names like Collier and Coulier from England, Kohler from Germany, Carbone from Italy and Spain, Carbon from France etc., all indicate that a person's ancestors were charcoal manufacturers. Charcoal is made by burning wood in a closed environment, by starting a fire and then cutting off the supply of air, allowing the water and sap to evaporate and other volatile chemicals in the wood to burn off, leaving only the carbonized wood behind. Of course, this means a supply of dry wood is needed to make charcoal, but since large forests were common in many regions, therefore this ingredient was easily available to everyone during the early days of gunpowder manufacturing. It must be noted that wood from certain types of trees makes better quality charcoal than others. The quality of charcoal is an important factor in the quality of the gunpowder, therefore the techniques of making high quality charcoal were very jealously guarded.

The second component, Sulfur, was also well known to everyone in the 13th century. In fact, it was known to ancient Egyptians, Indians, Chinese, Greeks etc. and mentioned in various literature from these countries. It is even mentioned in the Bible as brimstone. It commonly occurs in pure form in various parts of the world, particularly in volcanic regions and areas where hot springs are present.

Sulfur found naturally on the ground from the island of Vulcano in Italy.

Click on the image to enlarge. Public domain image.

In Europe, Sicily was a major exporter of sulfur since ancient times and it was also available near hot springs in most other countries, therefore gunpowder manufacturers could easily find sulfur from various places.

The third component, saltpeter, was the problematic one. It is the largest component of gunpowder and was the hardest to find historically.

Saltpeter was also known since ancient times, but it is not so readily available everywhere in the world. It does occur naturally in some parts of the world, such as India, parts of Spain, Chile etc. and also in some caverns and cellars. It can also be manufactured by artificial means, but the process is very slow.

William Shakespeare alludes to saltpeter in his play, King Henry IV in act I, scene III:

"And that it was a great pity, so it was,
That villainous saltpetre should be digg'd
Out of the bowels of the harmless earth,
Which many a good tall fellow had destroyed
So cowardly; and, but for those vile guns,
He would himself have been a soldier."

Control of saltpeter meant the control of gunpowder, therefore many countries put a lot of thought into ensuring a supply of saltpeter. This is why saltpeter men had special privileges, which we studied in our previous post. Vast fortunes were made by those who dealt in saltpeter. King Hemchandra (or Hemu), from one of the largest kingdoms in northern India in the 16th century, was not from any royal family, but from a family of green-grocers, and he made his fortune by trading in saltpeter, before becoming the King. The East India Company, which was the world's first multinational corporation, and controlled about 50% of the world trade at one point (beat that, Walmart!), made huge profits from shipping saltpeter from India back to England. Even though the East India company was known for its business in cotton, silks, indigo, tea (it was the East India Company's tea that was thrown into the Boston harbor at the start of the American revolution), they also traded in saltpeter, so much so that about 15% of cargo volume on their ships was saltpeter and it was one of their largest sources of profit. Since the British controlled so much of the Indian saltpeter trade, the French put their best chemists to work to produce artificial sources of saltpeter.

Guano from certain birds and animals was also another important natural source of potassium nitrate. The Guano Islands Act passed by the US Congress in 1856, allowed Americans to take possession of any guano-covered islands not claimed by anyone else and incorporate them as part of the United States territory, until the guano was exhausted. During the US Civil War, bat guano was used to produce gunpowder. In 1879, Peru and Bolivia combined together to fight Chile for mining rights in the Atacama desert, in a conflict known as the Guano war (also known as the Saltpetre War or the War of the Pacific). The main reason for the conflict was because the region was rich in potassium nitrate (ordinary saltpeter) and sodium nitrate (also called Chile saltpeter). This region rapidly became one of the natural sources of saltpeter until World War I.

Therefore, a study of the history of gunpowder manufacturing is largely a study of the history of the production of potassium nitrate. In the following posts, we will study the history of how it was extracted, both from natural sources and artificial production methods.

What is a Saltpeter Man?

Back in the early days of firearms, the propellant used was black powder. One of the components of black powder is a substance called saltpeter (or saltpetre, in British spelling). Saltpeter is more accurately known as potassium nitrate. Of the three main components of gunpowder, this one was the hardest to obtain in Europe, during the renaissance period. In fact, during the earliest years of gunpowder manufacture in Europe, no one was sure if saltpeter was a mineral that could be mined, or was it something that could be cultivated. The name comes from the Latin words, "Sal Petrae", which means "salt of rock", since it has the appearance of a layer of salt encrusted on rocks. Since saltpeter is white in color and since Europe during the early renaissance, got their saltpeter from Asia, it was often referred to as "Chinese snow".

A sample of saltpeter.

With the rise of gunpowder usage in various European kingdoms, it became necessary for governments to secure their sources of saltpeter. For instance, during the reign of Henry VIII in England, most of the saltpeter used for gunpowder manufacture in England was imported. Many countries realized that these supplies could easily be disrupted and therefore looked to produce it domestically. This gave rise to a specialized profession: saltpeter men.

Saltpeter men were people who were trained to extract saltpeter from nitrated earth (we will study this process in detail in subsequent posts). Since it was such a vital ingredient, saltpeter men were actually given special privileges by governments. For instance, in France, the saltpetermen were issued royal warrants by the king, called droit de fouille (translated as "the right to dig"), which allowed them to dig any soil that they suspected contained nitrates, without compensating the owners. In England, similar laws were enacted as well. In fact, in 1646, a new law was passed in the English parliament that allowed saltpetermen to dig in likely places and if any person refused to allow them to dig on their property, that person could be prosecuted by the courts! They were also allowed to demand carts belonging to other people, to be used to transport the saltpeter, and exempt from any taxes or tolls on any of the roadways in England. In theory, the owners of the land that the saltpetermen were digging, were to be compensated for any damage caused by digging, but often, the compensation amount was not enough to cover the damages caused. Saltpetermen were not a popular sight in many areas and many were either beaten up, or bribed by farmers to stay away from their land.

A man digging saltpeter earth in a barn.

Saltpetermen were allowed to dig practically anywhere, including palaces and churches, with the full protection of the British King and many a landowner dreaded the sight of saltpetermen walking in and tasting his soil. In one incident, saltpetermen walked into the church in Chipping Norton and ripped out the seats and tore up the floor, leaving no place for people to sit or kneel in church.

We will study more about saltpeter production in subsequent posts, but suffice it to say that quite a few countries had laws for barns and cellars to be built without flooring, so as to allow saltpeter to form in there. In America, in 1642, a law in Boston declared that "every plantation within this colony shall erect a house in length 20 or 30 foote, and 20 foote wide within one-half year next coming. &c., to make saltpeter." This law was actually based on a similar law passed by the King of England in 1626, that required citizens around London to do the same thing. Similar laws existed in Germany and Sweden as well. In fact, Swedish barns were not allowed to have paving stones until about 1830 or so and farmers were required to supply a certain amount of nitrated earth every year, as part of their taxes!

In the next series of posts, we will study the production of saltpeter throughout the centuries. I promise it will be a very interesting read.

Pommel Bags

In our last couple of posts, we studied devices that people used to protect key parts of flintlock weapons from being exposed to wet weather, namely tompions and cows knees. Today, we will study another device that had its origins in Europe, but became very popular in the United States.

Pommel Bag from the 1870s. Click on the image to enlarge.

In the early 1800s, as settlers gradually started moving westward in the United States, many frontiersmen mounted on horseback, carried large bore pistols for protection. As the technology for repeating weapons was somewhat primitive, these were mostly single-shot models and therefore, each person would carry two or more pistols.

At that time, black powder was still the propellant used for firearms, but it does not burn properly when wet. Therefore, it was necessary to find some way to keep firearms functional, even in bad weather conditions. Of course, it is possible to carry a pistol within a person's clothing to protect it from bad weather, but the problem is that when the weather is cold or wet, people wear multiple layers of clothing to stay warm, which makes the pistol harder to access.

One way around this was to put the pistol in a container, attached to the saddle on the horse. The pommel bag (such as the example above) had a separate compartment designed to hold a firearm, and the cover flap on top kept the rain and snow away. Pommel bags were typically mounted across the front of the saddle and attached to the saddle pommel (which is why they are called pommel bags). This makes it easy for a person to reach into a pommel bag, even when riding the horse. To access the firearm, the user merely had to lift the cover flap to get to it. The pommel bag often carried some additional gear for the pistol, such as extra cartridges, bullet molds, cleaning supplies etc.

When revolver models such as the Walker Colt revolver and the Colt Dragoon revolver came to the market, they were heavy weapons that were impractical to carry on a person, therefore pommel holsters were usually the preferred way of carrying them. The US military even issued holsters for cavalry in the 1850s, designed to carry these heavy revolvers.

A standard issue US military holster from around 1850. Click on the image to enlarge

The above image shows a pair of pommel holsters issued by the US Army around 1850. These were made to hold a pair of Colt Dragoon revolvers.