She silently watched him go up the stairs, feeling that she would strangle at the pain in her throat. With the sound of his feet dying away in the uppper hall was dying the last thing in the world that mattered. She knew now that there was no appeal of emotion or reason which would turn that cool brain from its verdict. She knew now that he had meant every word he said, lightly though some of them had been spoken. She knew because she sensed in him something strong, unyielding, implacable - all the qualities she had looked for in Ashley and never found.

She had never understood either of the men she had loved and so she had lost them both. Now, she had a fumbling knowledge that, had she ever understood Ashley, she would never have loved him; had she ever understood Rhett, she would never have lost him. She wondered forlornly if she had ever really understood anyone in the world.

* "Is this line baffling or crystal clear? It's just this equality sign. I'm very sorry about that."

* "There are three things here which are equivalent and two of them will be immediately useful. As for the third, I can't remember the use of that."

* "We're going on to something no more and no less abstract, but a little more familiar. And that is division."

* "I'm just going to state one more lemma that's so painful to work through that I'm not going to. It's almost as painful to write down, but that we'll have to live with."

* "a will always be 1625 and b will always be 299...at least they'll be that way for about four or five minutes."

* "Now, you will not mind if we don't prove this."

* "Amazingly, the result still holds, even though it makes no sense."

* "Now here's a question to which I don't really know the answer..."

* "It just strikes me that although that fact is obvious, it is not...obvious."

* "I have a strong feeling that it is an integral domain. Maybe it requires some proof."

* "And here's something I'm not really sure about..."

* "I nearly made one word out of 'a field'. There is as you know a word afield. It's a curious word. Can you be afield? You can go further afield. I would be willing to bet...*roots in pockets*...fifty cent that you can't be afield."

* "I never know when to stop calling things lemmas. I'm never sure when something is interesting enough to be called a theorem."

* "At the moment I can't remember why this is so."

* "Everything was perfectly ok, except for the very start."

* "Let x be an indeterminate. I don't know what that means, exactly..."

* "We'll be doing the sort of calculation that's been done since the year dot."

* "A right ideal is defined similarly. I leave that to your imaginations."

* "Let's not prove the claim. That's too hard. Let's look at a silly example."

* "This theorem is pretty well-defined. You can do most of it with your eyes shut."

* "There's a bit of mathematical mumbo-jumbo that you might want to go through..."

* "First of all, nobody would ask "Is five prime?" if it was."

* "It just introduces a rule for multiplying buckets."

* "...separates the elements into two buckets--I mean cosets..."

* (Draws a line down centre of blackboard. Steps back, examines it, shakes his head. Rubs it out and draws an identical line. Again, steps back, examines it, rubs it out. Draws another identical line down the centre of the blackboard.)"If I don't get the line perfectly in the middle, I won't be able to step on the cracks for a day."

* "I'm not quite sure if this is correct, but I'm willing to swallow it if you are. (Pause)Actually yes, I'm quite willing to swallow"

* "would you prefer me to use a vertical or a horizontal stroke? (pause) to clean the blackboard which is it?"

* "You won't find this in any textbook....I dreamt this up last week"

* "It's a complicated word for something that really isn't that simple anyway"

* A blown up condom is flying around the lecture theatre...Colm sees it and says "There was once a celebrated silent french film about a boy followed around by a red balloon"...returns to Matrix Algebra

* "There is no reason to believe the results are the same...except....they are the same!"

* "Here's something I like to do... now it might have no purpose"

* Guy leaves his lecture through the door down the front...Colm sees him and suddenly legs it across the lecture theatre out after him, terminator-style...returns several minutes later, studentless...continues with Matrix Algebra.

* Colm looks slightly confused by the pancake that has been left on the table for him on Pancake Tuesday. Slowly says..."But it's Ash Wednesday today...".

* Colm on probability: Asks the class "...So if I were to

I have received one letter and two texts so far this week from the Irish Blood Transfusion Service. There was a very high demand for blood in Dublin hospitals last month and this week the D'Olier St clinic is trying to replenish its stocks. Four hundred and fifty donations a week are needed. As of Tuesday evening, there had been one hundred and thirty.

One donation can save up to three people. It takes less than an hour and you get free food and drink, including Guinness if you wish. You will also find out what blood group you are, a handy thing to write on your passport.

The population of the greater Dublin area is over a million. Many more commute to Dublin every day to work. I find it shocking that of all these people not even four hundred and fifty can find an hour to care about the sick.

Please, please, even if you can't find it in your heart to become a regular blood donor, try to donate blood this week, preferably in the D'Olier St clinic. It's open till eight this (Thursday) evening and till five tomorrow. If you are unsure whether you can donate, visit www.ibts.ie to find out what the regulations are.