Tea – does the milk go in first?

Sir, – While I'm sure it's not intentional, it's inescapably true that when Owen Dawson comments that it "makes no difference" whether one puts tea or milk in a cup first, he is overturning the entire evidential basis of modern medical science (An Irishman's Diary, March 26th).

This is because a man offered a woman a cup of tea, which she declined, at Rothamsted in England the 1920s. The woman, Muriel Bristol, declined as she only liked tea when the milk had been put in the cup first. And it hadn’t.

The man, Ronald Fischer, expressed doubt that she could tell the difference.

More importantly, they being scientists, he designed an experiment to test her claim, with eight cups presented to her in random order.

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Another scientist present, William Roach, later her husband, recalled that she “correctly divined more than enough to prove her case”.

For anyone with a deeply nerdish interest in scientific history, this was the original formulation of the “Null hypothesis”. This, a key concept in statistics, holds that theories cannot actually be proven true, but will be accepted if experiments show their falsehood to be sufficiently unlikely (by convention, a less than one in 20 chance).

The experiment became the basis of “Fisher’s exact test”, which is still used to verify the effectiveness of novel or existing medical treatments. So, when one hears of “evidence-based medicine”, that, or something very similar, is usually the evidence.

Fisher’s name was thereby immortalised in medical and scientific history. Muriel Bristol, a mycologist or expert on fungi, meanwhile has a popular science book (The Lady Tasting Tea: How Statistics Revolutionised Science in the Twentieth Century, by David Salsburg) and a Wikipedia page dedicated to her. The latter tersely summarises “what she was known for: being able to determine whether the tea or the milk came first”. – Yours, etc,

BRIAN

O’BRIEN,

Kinsale,

Co Cork.

Sir, – Surely the answer to this important Irish question is best asked of our friends across the water in the UK?

However, it may depend on whether the respondent is a Leafer or a Restrainer. – Yours, etc,

ULTAN

Ó BROIN,

Florence.

Sir, – Owen Dawson brings me back to 1950s Belfast, when tea bags first made their appearance in our house. I watched as my mother carefully snipped each tea bag and poured its rather dusty contents into her tin tea caddy.

In 2019 Dublin, the rumour seems to be, however, that tea bags are not gluten free, and hence we sip delicately at sometimes hard to get “loose tea”. – Yours, etc,

ROBIN

HARTE,

Strawberry Beds,

Co Dublin.