Last year, I spent one beautiful afternoon driving back roads through the Rocky Mountains with my friend Thern, who is a Mechanical Engineer.
I don’t recall the conversation exactly, but at some point I was complaining about receiving an engineering drawing in mils. My friend swiftly turned his head, looked me in the eyes and said “mils are a bullshit, made-up unit.” I found his visceral, candid and accurate response refreshing. When later talking with Sven, another pro-metric friend, about mils, I thought I heard him call them “feral units.” The designation was perfect. A feral organism is one that has changed from being domesticated, to being wild or untamed. The word derives from the Latin word fera which means “a wild beast.” A mil is a feral engineering unit indeed.
What is a mil? Well, according to engineering folklore a mil is one-thousandth of an inch. The British use the word mil as a slang term for millimeter. Confusing a unit which is 25 um with one that is 1000 um, is an error of about a factor of about 40. When American
engineers work with British engineers on a project, this could be the source of some serious mistakes.
The two feral units which are probably the most dangerous to humans, you probably use every time you follow a cooking recipe. They are the teaspoon and tablespoon. Some readers may almost find this assertion preposterous, but, as I will demonstrate, it is not. In America we use the abbreviations Tsp for teaspoon, and Tbl for tablespoon.
When I was growing up, and became sick, my mother would obtain liquid medicine from a doctor, and then obtain a teaspoon or tablespoon from our silverware drawer. Unfortunately, there is no requirement that a teaspoon or tablespoon of flatware hold a prescribed volume. The label on the brown bottle would have the dosages typewritten in terms of teaspoons or tablespoons.
If one looks at a set of measuring spoons used in cooking, metric equivalents are generally stamped or printed on them. A teaspoon is designated as 5 mL and a tablespoon is 15 mL. (In Australia a
teaspoon tablespoon is 20 mL) The ratio in volume is obviously three. It is well known that the abbreviations Tsp and Tbl are easily confused. This has led to cases of people receiving 1/3 of the required dosage of a medicine or three times the recommended dosage. Not long ago I exchanged emails with a woman who has become interested in metric issues because her child was incorrectly medicated because of Tsp versus Tbl. Studies indicate that approximately 98,000 Americans die each year from incorrect dosage, and medical errors which can be directly tied back to the lack of the Metric System in the United States
How long has the medical establishment known about the danger posed by feral units? I’m not sure, but here is a column from The Journal of The American Medical Association, dated September 20, 1902 (page 712):
The problem has been understood for over 100 years, since the days of John Shafroth, but nothing is as permanent as American inaction when it comes to adopting the metric system. This adoption must be mandatory and exclusive. It is my understanding, that legislation mandating over the counter medicines include dosage cups with milliliters, has been perennially thwarted by business and industry.
America is a country that is very sensitive to the welfare of children. The population at most risk from large dosage mistakes are children, yet this needless endangerment continues–only in America. All other countries (except Myanmar and Liberia) are metric and this is not a health issue. Clearly, feral units that wander the shelves of America have the potential to kill.
The ferocity of Tsp and Tbl are anemic by comparison to the difference between gram and grain. A gram is a metric unit, a grain?–well here what Wikipedia has to say:
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass.
They go on:
The fundamental unit of the troy, apothecary and avoirdupois systems, commonly known as the grain (or less commonly the barleycorn), is nominally based on the grain of barley.
Well, there isn’t just one type of grain for mass, there is the grain, the troy grain, the pearl grain and the metric grain. Don’t even get me started on the insanity of mixed “units” like metric grain and metric ton. The grain we generally talk about is the one where 7000 grains are equal to one avoirdupois pound.
I might hear you say, but we don’t weigh things in grains. Well here is Wikipedia again:
The grain is used to measure the mass of bullets, gunpowder, smokeless powder, and preformed gold foil; it is the measure used by the balances used in handloading; bullets are measured in increments of one grain, gunpowder in increments of 0.1 grains. Moreover, the grain is used to weigh fencing equipment, including the foil. In archery, the grain is used to weigh arrows and arrow parts.
Unfortunately the grain is also sometimes used in medical prescriptions in the US, this is where an almost 65:1 error is possible. If the only legal system for trade in the US was exclusively the metric system, and it was enforced, it’s all grams—period, it’s all milliliters—period, it’s the simplest way known to describe these quantities—period.
This is true only if we use accepted SI designations. For instance, the abbreviation for milligram is mg and microgram is μg. This is very important as the dosage difference between milligram and microgram is a factor of 1000. Unfortunately, vitamin bottles use MG for milligram and MCG for microgram. These are feral designations.
A Dateline NBC program entitled: “The Validity of Vitamin Bottle Labels” which aired on March 18, 2012, relates the story of a number of women who were poisoned taking vitamins. There is no regulation of natural “dietary supplements” so anyone can start a vitamin company. Anyone can just send a list of ingredients to a chemical vendor and create a “dietary supplement,” and offer it for sale to the public. One business used MG when the dosage was supposed to be MCG for the amount of Selenium dioxide in a “dietary supplement” concoction. Women taking this “supplement” began to lose their hair, nails, and had joint pain. The use of feral metric designations in medicine, endangers the public health.
It is long past time for the US to require only the domesticated metric units used by the rest of the world. Feral units can then be safely isolated in a museum for all to gaze upon, knowing they are safely confined, where they can do no harm.
Updated 2012-07-11 The information that approximately 98,000 Americans die each year from the lack of metric was added. It was pointed out by a reader, that I also used teaspoon instead of tablespoon in describing the 20 mL measure used in Australia. This was unintentional, and shows the ease of confusion.
If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page.