In the original text -- the song was updated to the first world war -- a Confederate agent asks the ladies of Montgomery, Alabama, to save their night water, so that saltpeter necessary for the manufacture of gunpowder might be extracted.
Said to date from 1864 and a request made in either Selma or Montgomery, Alabama.
By the later portion of the 20th Century, this ballad had apparently fallen out of oral currency. - EC
In earlier editions of the Index, I questioned the truth of this report, simply because Union troops were so late in reaching central Alabama. But the request need not have been local to that area. Saltpeter (needed to make black powder) was not available in many parts of the south, and Isaac M. St. John (1827-1880), chief of the Mining and Nitre Bureau, did appeal to southern women to save the contents of their chamber pots.
Saltpeter had always been a useful product. Even in ancient times, it was used by fullers and dyers; it helped fix colors, and also helped create some otherwise hard-to-achieve hues.
It appears that saltpeter in ancient times was not a precise term. It seems to have been used most often for potassium nitrate, KNO3, but other nitrates such as sodium nitrate (NaNO3, sometimes called "Chile saltpeter" or "caliche") were sometimes used before chemistry became more precise. For many purposes, the difference between nitrate types was rather minor; it was the nitrate that gave the "bang" -- and also contained the nitrogen which made waste materials a good fertilizer. (Note that ammonium nitrate, NH4NO3, which might have been considered a saltpeter by the ancients, is still used as a fertilizer and as the basis for explosives! Sodium nitrate does not make as good a gunpowder as potassium nitrate, since it is more likely to absorb water and degrade, but the two are relatively easy to convert; Bown, p. 148)
But natural saltpeter was rare. Early on, it was discovered that it could be manufactured from animal wastes. Mammal urine contain urea (CO(NH2)2), and bird droppings contain uric acid (C5H4N4O3), both of which could be reacted with alkalis to produce saltpeter. The usual method was to place the droppings on an alkaline soil and then going through various purifying steps (see Stephen R. Bown, _A Most Damnable Invention: Dynamite, Nitrates, and the Making of the Modern World_, Dunne, 2005, pp. 28-33).
As early as Roman times, then, we see dyers collecting their own urine, plus whatever others wanted to donate. This was adequate for cloth manufacture, but it left no excess.
And then the demand skyrocketed. The reason is simple: Black powder (gunpowder) consists of sulfur, charcoal (carbon), and saltpeter.
From the start, saltpeter was the largest component; Roger Bacon's formula in the thirteenth century was five parts charcoal, five parts sulfur, seven parts saltpeter (so John Emsley, _Nature's Building Blocks: An A-Z Guide to the Elements_, corrected edition, Oxford, 2003, p. 412). But it was quickly found that more saltpeter was better; Charles Henry Ashdown, _European Arms & Armor_ (I use the 1995 Barnes & Noble edition, which appears to be a reprint though no information is given on the original publication), p. 361, says that "Schwartz, a German Frank, perfected it about a century [after Bacon]." This would mean that Edward IV, for instance, would use the more modern formulation -- and, indeed, when he invaded France in the 1470s, we find that he had need to carry with him "hundreds of shot of stone, barrels of gunpowder, sulphur, brimstone, saltpetre" (see Elizabth Jenkins, _The Princes in the Tower_, Coward McCann, & Geoghan, 1978, p. 104). It's not clear why sulfur is mentioned twice and charcoal not at all (perhaps the English expected to make the charcoal on the spot?), but it is clear that no one expected local supplies of saltpeter or sulfur to be adequate.
By the time the use of gunpowder was widespread, the saltpeter made up two-thirds to three-quarters of the total, yet it was the hardest component to find and to purify. With limited natural supplies. saltpeter had to be manufactured on a large scale.
Which meant -- let's face it -- that a lot of waste had to be gathered and processed. According to Bown, pp. 33-34, it was Charles I of England who in 1626 made what was apparently the earliest proclamation ordering people to collect the contents of their chamber pots. (It almost makes you wonder if that's why they rebelled against him.) The result was the institution of the "saltpetermen" or "petermen" (Bown, pp. 36-38) -- people whose intrusive behavior hardly endeared them to the population. It's interesting to note that, in later usage, the word "peterman" came to mean a thief.
Bown, p. 47, goes so far as to argue that France lost the Seven Years' War in part due to saltpeter shortage. I have not seen this claim advanced in any of the usual histories of the period, however.
After a time the dirty business was exported, mostly to India (Bown, p. 40), where there were lots and lots of people -- which meant both lots of human waste and lots of unemployed people to process it. Later, an even more concentrated source was found in the bat and bird guano found in Latin America (Floyd L. Darrow, _The Story of Chemistry_, Chautauqua Press, 1928, p. 216, says that Chilean saltpeter began to be exported in 1830; see also "Tommy's Gone to Hilo"). Bown, p. 149, implies that caliche was in use even before that, being used to make gunpowder during the Napoleonic Wars. It wasn't until the twentieth century that the Haber process made it possible to extract atmospheric nitrogen. Until then, a country had to either import nitrates or make them.
A nation at war burned through its supplies quickly. During the Napoleonic Wars, Britain is said to have imported 20,000 tons of saltpeter a year (Bown, p. 48).
The Confederacy probably needed even more. The standard charge of a Civil War rifle musket was 60 grains, or 4 grams. So that's 3 grams of saltpeter. A typical infantryman carried 40 rounds when going into battle -- 120 grams. (He would often fire far more rounds than that, to be sure.) Let's say that there were 75,000 Confederate soldiers at Gettysburg (which is about right). The typical soldier probably fired about 65 rounds. So that's 75,000 soldiers times 65 rounds times 3 grams, or 14,625,000 grams. 14,625 kilograms. 15 tons of saltpeter just for the *infantrymen* in one single battle. Artillery, which took much larger charges, would have required even more.
And the Confederacy spent the entire war under Union blockade. Importing by land was impossible; whatever they had had to come in by sea. Initially blockade runners could bring in some. But the blockade tightened as the war progressed. By 1863, the blockade was pretty tight. That left domestic manufacture as the only source of saltpeter. Hence the collection of slops from Confederate bedrooms -- and hence this song.
Incidentally, even the replacement of gunpowder with smokeless powders did not eliminate the need for nitrates. Nitroglycerin and its successors required nitric acid, and this too was derived from saltpeter and its relatives. Cordite, for instance, the propellant in British firearms, consisted of nitroglycerin and guncotton (both of which required nitrates to manufacture) plus vaseline. During World War I, therefore, nitrates once again became an issue -- Germany had the Haber process, but the Entente powers were still using Chilean saltpeter, according to Darrow, p. 215.
(As a matter of fact, some historians, cited by Bown, p. 218, speculate that Germany did not dare start World War I until the Haber process guaranteed their nitrate supply. I grant that, until 1914, the Germans hadn't pushed diplomatic crises so hard -- but World War I came about largely because of the ineptitude of Wilhelm II of Germany and Franz Joseph of Austria, and what are the odds that either of them made such calculations?)
(Haber's work would earn him the Nobel Prize in chemistry, and it was surely deserved. The award had to be given almost in secret, however, because he had spent the bulk of the Great War working on poison gas. He was not someone you would want to know; his role in gas warfare actually led his first wife to commit suicide -- Bown, p. 226.)
There was a brief time after the Battle of Coronel when Graf Spee's German fleet had driven the English away from Chile.Britain moved instantly to crush Graf Spee's fleet (which they would do at the Battle of the Falkland Islands). Most histories of World War I viewed this as an issue of prestige, but Darrow, p. 216, argues that the saltpeter was needed for the war effort, and Bown, p. 192, thinks this was a reason for the swift British response, though he admits there is no evidence for this. Bown, p. 198, argues that the infamous "shell shortage" of 1915 was also due to nitrate bottlenecks, though most histories simply assert "manufacturing difficulties." My guess is, British factories had enough nitrates for the amount of shell they actually were able to provide but would not have had enough to make all the weapons the generals wanted -- note that, according to Bown, p. 200, nitrate exports from Chile increased 50% during the War even though Germany was completely cut off from the market. At one time, according to Bown, p. 201, there was a 300% price premium during the war.
Even in the period after the Great War, Darrow (p. 229) notes that the United States maintained a Fixed Nitrogen Research Laboratory. As late as the 1920s, Chile was still supplying almost a third of the world's nitrates (Darrow, p. 230), though refinements of the Haber process were rapidly making more available, and new research also allowed nitrogen to be extracted from coal as it was converted to coke. It wasn't until 1926 (according to the numbers in Darrow, p. 233) that the nitrate business really began to decline -- the stocks of the companies fell by more than 50% in that year. - RBW