_Swot_ is, as the querist supposes, a military cant term, and
a sufficiently vulgar one too. It originated at the great
slang-manufactory for the army, the Royal Military College, Sandhurst.
You may depend upon the following account of it, which I had many
years ago from the late Thomas Leybourne, F.R.S., Senior Professor of
Mathematics in that college.
One of the Professors, Dr. William Wallace, in addition to his being a
Scotchman, had a bald head, and an exceedingly "broad Scotch" accent,
besides a not very delicate discrimination in the choice of his
English terms relating to social life. It happened on one hot summer's
day, nearly half a century ago, that he had been teaching a class,
and had worked himself into a considerable effusion from the skin. He
took out his handkerchief, rubbed his head and forehead violently, and
exclaimed in his Perthshire dialect,--"_It maks one swot_." This was
a God-send to the "gentlemen cadets," wishing to achieve a notoriety
as wits and slangsters; and mathematics generally ever after became
_swot_, and mathematicians _swots_. I have often heard it said:--"I
never could do _swot_ well, Sir;" and "these dull fellows, the
_swots_, can talk of nothing but triangles and equations."
I should have thought that the _sheer disgustingness_ of the
idea would have shut the word out of the vocabularies of English
_gentlemen_. It remains nevertheless a standard term in the vocabulary
of an English soldier. It is well, at all events, that future ages
should know its etymology.