James Le Fanu

‘For every problem there is a solution: neat, plausible and wrong’. H.L.Mencken

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Our bodies are the best measuring stick of our world

DESPITE the 30 years that have elapsed since the official conversion from Fahrenheit to Celsius, I remain resolutely a Fahrenheit man. Give me a reading anywhere between 97 degrees and 104 degrees, and almost instinctively I can assess the severity of the fever and the illness that is causing it. The Celsius equivalents, by contrast, seem quite as meaningless as when they were first introduced.

My failure to make the necessary mental adjustments could be attributed to the customary difficulty of old dogs learning new tricks – but I suspect it is something more than that. A fever of 100 degrees F feels hot in a way that a fever of 40 degrees C never can.

Like everyone else, no doubt I’ve experienced precisely the same difficulties in making the transition from the Imperial system of measurement of pounds and ounces to the metric system of grams and kilograms – as required by the diktat of a European directive that came into force on the first day of the new Millennium. Once again the lack of familiarity with the new system is only part of the problem.

The point is best illustrated by considering first why we should feel that the date when the new regulations came into force – the 2,000th anniversary (or thereabouts) of the birth of Christ – was worth celebrating. The appeal of counting in 10 and multiples thereof, such as hundreds and thousands, is obvious enough. We have 10 fingers, and finger-counting is both the earliest and simplest method of reckoning. Hence the term digit, which is derived from the Latin digitus, a finger.

The Mayans and various tribes in north and western Europe, including Britain, went, as it were, a bit further, and included their toes, so they counted in twenties. Vestiges of this system of counting can still be seen in the English word score, which alludes to the notch shepherds would make on a stick after counting 20 sheep.

There is thus an obvious rationale for the decimal system, based on our ready familiarity with the number of fingers and toes we possess. The same practical arguments apply to the traditional Imperial system of expressing lengths in terms of inches, feet and yards, each of which is based on an approximation of the length of a part of the body: the inch being the length of the terminal phalanx of the thumb; a foot being a foot; and a yard three feet placed one after the other. Hence, when ordering a piece of wood 3ft 6in long, we know instinctively what its dimensions will be.

By contrast, the metric system is an entirely arbitrary method of measurement, instigated by the Utopian radicals of the French Revolution, and bears no relationship at all to the parameters of the human body. The standard metre is derived from “one 10-millionth part of a meridional quadrant of the earth” (whatever that may be), while the gram, the basic unit of weight, was defined as the mass of an equally arbitrary “cubic centimetre of pure water at the temperature of its maximum density”.

But the metric system is not only divorced from any readily recognisable analogy with the dimensions of the human body, it is also a dismal failure in practical terms. Centimetres are far too small, while the next unit up, a metre, is simply far too large. Similarly, whereas the pounds, ounces and pints of the old Imperial system are useful practical measures for cooking, their metric equivalents are either too fussy or too unwieldy. Thus the arguments in favour of metrication, just as for the changeover from Fahrenheit to Celsius, are entirely spurious. As human beings, we need a practical, workable method for estimating the parameters of the world around us, and the best way of doing so is by referring to something with which we are all familiar – ourselves.

Human saliva, or spittle, as they call it up north, helps heal cuts and abrasions, thanks to a natural chemical call lysozyme – hence the origin of the term “kiss it better”. Now I learn there is a similar scientific rationale for saliva’s “spit and polish” cleaning properties.

“Conservators prefer their own saliva to any other solvent for cleaning fragile paint and gold leaf surfaces,” observes Dr Paula Ramao, of Portugal. Accordingly, she has conducted a scientific experiment to compare its effectiveness against commercial solvents, such as white spirit and dilute ammonia.

The experiment “confirmed saliva as the best cleaner”, Dr Ramao found. She attributes this to two factors. The aqueous component of saliva has a washing action, while an enzyme called alpha amylase disrupts the fatty proteinaceous composition of soiled surfaces and thus “catalyses dirt degradation”.