These lines are taken from a Danish ballad called The Ghaist's Warning. A translation appears in an appendix to Walter Scott's poem The Lady of the Lake.
Nelly's couplet isn't quite accurate. It should be:
Twas lang i' the night, and the bairnies grat:
Their mither she under the mools heard that;
An approximate translation:
It was late, and the children wept,
Their mother beneath the earth heard that,
The Ghaist's Warning can be found here with an accompanying glossary.
Cathy is referring to Milo of Croton, an Olympic wrestler and soldier of the 6th century BC, who died whilst attempting to tear a tree apart with his bare hands. They became trapped in the cleft of its trunk and he was set upon by a pack of wolves.
Crotone is a small city in Calabria, Italy.
One of the most famous quotes from the book, this line sums up the depth of Cathy's feelings for Heathcliff. She is not in love with him, she is him, they are not two people but one and the same. The line is often used in promotional material for television and film adaptations of the book such as this trailer for the ITV1 production of Wuthering Heights in the UK.
The same intoxicating approach was taken by Richard Wagner in his Tristan and Isolde, another highly-wrought and ill-fated romance, written less than ten years later:
You Tristan, I Isolde, no more Tristan!
You Isolde, I Tristan, no more Isolde!
Blood-letting was a common medical practice at the time. Physicians believed that removing blood could be beneficial to health. The objective was to balance the humours (blood, phlegm, black bile and yellow bile) as an excess of one humour over another was thought to cause poor health. Blood was associated with Spring, and so excesses were expected in this season.
There are parallels in other medical traditions, including Ayurvedic and Chinese medicine, which also stress internal balances.
A scholarship awarded by Cambridge University and Trinity College, Dublin.
Emily Brontё's father was a sizar at Cambridge.