Thursday, September 5, 2019

Whatever happened to white dog shit? Part two

As part of my ongoing research into the scarcity of white dog shit these days (see my previous note on the subject), I've decided to post this note with new information that has come to light on the important topic of white dog shit. The first two points of this note expand and refine my previous discussion on why white dog shit has become rarer. What's new and exciting however is the third section, which discusses the uses of white dog shit, and particularly the use of white dog shit in the leather industry.

1. Theories of white dog shit scarcity.

There are two main theories that try to explain why white dog shit is less common than it once was.

A) The Dietary Shift theory that says something changed in dog's diets some time in the 1980s that reduced the incidence of white dog shit. Many proponents of this theory say that a diet rich in bones was responsible for dog shit turning white, and this is supported by the fact that wild dog shit usually turns white. Changes in commercial dog food formulas around this time (e.g. the amount of bone in the food) may also have been responsible.

B) The Legal Theory that says dog control laws and laws requiring owners to pick up their dog's shit are responsible. This leads to less dog shit left in the open to turn white. The appearance of such laws around the 1990s coincides well with the generally accepted time frame of white dog shit disappearance.

There is also a Hybrid Theory that says both of these factors are responsible.

2. Chemistry of dog shit.

Shit generated by mammals contains a chemical called bilirubin, which is formed in the liver by the breakdown of the porphyrin ring of hemoglobin from red blood cells. This chemical is concentrated and excreted in the bile, and it is this chemical which is responsible for the most of the brown color of shit. Bilirubin breaks down in light, and this would account for the bleaching of dog shit in the sun. Also, when exposed to light, bilirubin isomerises and this photo-isomer is more soluble in water than the unilluminated isomer. This might account for some bleaching in conditions where water is present to remove the isomerized bilirubin, however the solubility of iso-bilirubin is still too low to account for significant bleaching. Further examination of dog shit undergoing the whitening process indicates that white dog shit is initially only white on the outside. This would support the idea of bleaching by light. The method by which the inner core of older specimens becomes white remains a mystery, although decomposition by bacteria is probably an important factor. White dog shit is believed to be composed mostly of calcium phosphate, the main mineral that forms bone. After the dog shit decomposes, what is left is a block of mostly calcium phosphate, with additional minerals, colorless proteins and organic chemicals.

3. Uses of white dog shit.

In Victorian England white dog shit was known as "Dog Pure" or "Dog Puer". There used to be a class of laborers known as a "Pures Collectors" who wandered the streets with baskets collecting white dog shit to sell to leather tanneries. Some even had connections to kennels where they could get a ready supply of the material. White dog shit was used because of the pancreatic enzymes present in the dog pure, which break down the non-collagenous proteins in the hide. Dog pure was used for "Puering", which is the process of softening the leather prior to tanning. Dog pure was used to prepare the extra-soft, more expensive leather used for making ladies' gloves, book covers etc, although pigeon shit was used for the finest leather. Indeed, a tannery of orthopedic leather in Colyton, Devon had a "dog shit pit" up until the 1960s, and it was said to be a foul hole.

"Pure Finding" was a well established career by 1851, but by 1935 it had disappeared. As a source of income it paid about 8 shillings per bucket. However, due to a worsening economic climate, and the popularity of pure finding as a career for those without recognized skills, the revenue eventually fell to about 1 shilling and sixpence per bucket.

There is a song about pures collectors inspired by the work of Victorian social researcher Henry Mayhew:

By the 1980s chicken guano replaced dog pure, as it was easier to obtain and still provided the same high quality results. Later, a pancreatic extract from pigs replaced dung in leather processing. Also, because dog shit can spread serious disease in humans, pure finding was discouraged from a health standpoint.

As with any profession, pures collectors had their tricks. They knew the dry limy-looking dog shit fetched the highest price as it contained the leather softening properties but didn't foul the leather. This led to the idea of adulterating dog pure. This was done by means of mortar broken away from old walls and mixed with the dog pure. In some cases the material was rolled into small balls similar in appearance to real dog pure.

Although dog pure is no longer used in leather processing, there are still those in the industry who believe dog pure was the best agent for softening leather. However, due to modern methods of mass producing leather and the health issues, white dog shit is unlikely to return to favor as a softening agent in anything other than small scale leather production.

In medievil medicine white dog shit was known as album graecum and was an ingredient in gargles and plasters for various ailments. An example is this gargle for Quinsy (a peritonsillar abcess):

A Gargle for a Quinsy.

Take Columbines 2 handfuls; inner rind of Elm 1 ounce; Jews Ears, Liquorice, Album Graecum, each half an ounce; boil in Water 2 pints and half to 26 ounces; in the strain'd dissolve Salt Armoniac 2 drams; Syrup of Raspberries, Honey of Roses, each 3 ounces.

It humects, foments and mollifies the Muscles of the Throat, when inflam'd, swol'n up 'till almost crack'd, parch'd and scorch'd with Drought and Heat. It deterges the Glands and salivale Ducts, when outwardly smear'd over with Slime, and opens them when inwardly stuffed up with Phlegm.

As you can see from this discussion, white dog shit research is advancing considerably. Not only are the theories of its scarcity being refined, but the chemistry of its formation is being explained. Also, the historical, cultural and economic contributions of white dog shit to our society are beginning to be appreciated. The next step will be to find more uses for this important natural resource.

Be sure to check out my original post about the disappearance of white dog shit, which was inspired by Ben Elton's 1990s comedy skit about white dog shit.

4. ENG-LIVERPOOL-L Archives, Middens and More, by Barbara Humphreys.
8. Pharmacopoeia Extemporanea, by Fuller.

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