There's an old American saying: "From shirtsleeves to shirt sleeves in three generations."

Not surprisingly this phrase became current during the era - the 1870s and 80s - the era of the so-called "Robber Barons", when poor immigrants - Andrew Carnegie, John D Rockefeller were spectacular examples - arrived in an industrial town, laboured relentlessly, spotted the possibilities in some humble element they worked on - coal, coke.

With the young clerk, Rockefeller, it was a sticky oil that oozed from the ground which the Indians had used as a laxative.

The young clerk sank his modest savings in this ooze and it turned him into the head of Standard Oil and made JD Rockefeller what one old diarist called "a leviathan of wealth".

But both Carnegie and Rockefeller, once they'd acquired their fortune, spent the rest of their lives dispersing it, in medical, educational and other philanthropic institutions which, to this day, are towering testaments to the value of research unfettered by government.

But many more smaller figures of the Robber Baron age made immense fortunes, took no care of them, were not of a generous or philanthropic nature, handed the money on as a life belt to their sons who then squandered it, so much so that their sons returned to the shirtsleeves in which grandfather had landed in the United States.

Hence the merciless phrase: "From shirtsleeves to shirt sleeves in three generations."

This phrase came back to me one day last week when I read a melancholy list, a long list, of dot.com domains that had vanished from the internet, signifying the dot.com millionaires who had gone belly-up.

The 1980s fly-by-night youngsters who got out of college, rounded up two pals, thought up a funny or fascinating little company and within two, three years were buying a townhouse and a million dollar pad at the Hamptons or the Jersey shore.

I knew one of them, a charming young late-30ish man who bought himself, amazingly, two years ago a $2m country house on a bay.

He put it up for sale this year at twice the price, isn't going to get it and has vanished without trace.

I hope the nucleus of his wealth was conservatively saved or he may be seen as the vanguard of yet another American generation which repeats the experience of "shirtsleeves to shirtsleeves in three generations".

It's not a pleasant chore to read through this melancholy list but for a reporter, at least, it has an upside: Once you've cleared away all those dot.com fly-by-nights there's more room left to notice how interesting are some of the modest dot.coms who are left and succeeding.

Here are two that came to my attention in the past few weeks:

The first is an oddity indeed, since it's a company that was set up, you might say, to flourish only once a year. It's called revengeunlimited.com.

A website started by a man in Florida a little more than three years ago, it's designed to send a nasty product to somebody you want to get even with - people you've had a row with, people who've insulted one of your family, people whose public behaviour has disgusted or alarmed you.

One or two distinguished potential recipients come to mind. The gift of choice is a bunch or box of roses - black or dead.

The season for dispatching these presents is short but very busy, in and around Valentine's Day of course.

A Mr Baumgartner who thought up and runs revengeunlimited.com spent, with his helpers, several 18-hour days last week boxing dead, black or lopped-off roses for close to 300 clients.

Also just up the coast, the east coast of Florida, is an equally enterprising woman, once an airline stewardess who now makes a better living hiring four full-time helpers and an army of teenagers on Valentine's Day.

She calls her business the Drop Dead Florist and her website is dropdeadflorist.com. She has 6,000 roses wilting away in her garage but does not restrict her profitable insults to roses.

If you feel particularly sore at the treacherous loved one you can have the Drop Dead Florist despatch her or him a box of melted chocolates or a dead fish.

Both Revenge Unlimited and Drop Dead Florist say that most of the year, the slack time, is devoted to people who just have a grudge of one sort or another but of course the great busy season has just passed.

Next year they expect, both of them, to double their business - next Valentine's Day.

They see no end to their potential clients if only they can become better known to the disconsolate, the melancholy, the torch bearers, the worldwide army of the jilted.

The second exhibit of prospering oddities sounds bizarre, to some people demented. It embodies a scientific discovery which has transformed the field of taxidermy.

It's called "freeze a pet" and means exactly what it says. If you can't bear the loss of your precious dog or cat now you can have him/her frozen in a favourite pose, physical attitude, and it can be guaranteed to outlive you, however long that may be.

There are just over 70m pet owners in the United States and it seems that every year more and more of them turn to the freeze-drying process developed in the past six or seven years.

It has, I'm told, given a progressive jolt to the whole field of taxidermy, namely to museums of natural history - replacing, in many of them, the traditional method which involves first skinning an animal, removing its intestines, cleaning away the muscle and other tissue, then restructuring the bones and tanning the hide - an elaborate, tedious and costly process.

In freeze-drying, Pompey or Fido is left as he was. The mourning owner can offer snapshots or whatever to pick a favourite pose and the taxidermist so arranges the pet. It is then frozen solid.

Now - and here's the telling difference - it goes into a steel cylinder with a very thick plexiglass window. This is the freeze dryer, which cools the animal to 12 degrees - that's 20 below freezing. Simultaneously a pump is at work sucking out the air leaving a true vacuum.

So as Fido cools what happens to the ice? Ah, that's the great difference. The ice does not melt into water, it escapes as vapour.

So the crucial advantage of this method is that the pet does not decay and therefore does not, as most reconstituted museum specimens do - or did - become in time infested with insects.

Incidentally it's an interesting sidelight on the human species that when this method is described to people as a way of preserving the lamented pet some people wince and mutter something like "disgusting" or "obscene" but describe it as the latest superior method for preserving the flamingo or the Serengeti leopard in your museum of natural history and the audience says "how marvellous".

Did you notice this switch in yourself just now?

The process, whose singular virtue is to evaporate water into vapour without any intervening ice, was invented by American army doctors during the Second World War as a method - the method - of preserving blood plasma.

It was, I regret to tell you, a story - kept secret at the time - which one government department or another (I forget which) put me on to when for five months in 1942 I went off on a trip all around the United States to report on what the war had done to every conceivable trade, crop, profession, from fattening pigs in record speed to tattooing, to the manufacturing of fake rubber.

I was told I could see this blood plasma process but I didn't understand it and I never followed it up. Stupido!

However, just at the same time and in the same state of Florida I did hear an unlikely story and I got in on one of the unique medical stories of the war.

On the beautiful west coast of the Florida peninsular, in what was then a very small village - it's now a resort - the department of agriculture sent me to a tousle-headed professor of biochemistry who'd been drafted by the government and set up in a shack in this tucked away village.

And this was the problem who'd been set: The success of the Nazi submarine campaign on both sides of the Atlantic - off the Jersey and eastern shores here and of course all around Britain - had taken a toll in many ways.

The children of Britain were chronically short of citrus, ascorbic acid, vitamin C, lemons, limes - Florida had millions of oranges for shipment.

But a case of oranges took up as much room in a ship as a case of shells or guns or other weapons which the United States was at that point shipping to Britain.

The tousle-headed professor discovered, under my very eyes, a method of concentrating the juice of the orange which was then shipped to Britain, along with a simple instruction: "Add five pints of water to one pint of this concentrate and you'll still have whole orange juice."

It was a brilliant success and guaranteed that whatever else the embattled children of Britain might die of, scurvy would not be it.

If only I'd had the wit as soon as the war was over to invest my modest savings and take the leap aboard the commercial company that swiftly moved into that Florida village and made many fortunes.

If! I might now be lolling in my Palm Beach mansion instead of sitting here in my shirtsleeves writing letters to people in Libya and Bombay and Australia and Little Piddletrenthide.

I saw the secret but I never made a penny out of it. Bing Crosby did.

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