These days the kids from the Treasury, in their TM Lewin's and after-dinner-mint-thin-laptops, turn-up their noses at such artless thinking.
Politicians, always keen to spot a revenue raising idea; in 1888 the motor car was causing havoc and the vehicle excise duty was born. It was a fiver. About �500 in today's money.
It was chancellor and famous Liberal, David Lloyd George who said, in 1910, the proceeds of vehicle excise duties would make the road system 'self-financing'. It didn't.
In 1920 the tax was ring fenced for the construction of better highways. That carried on until 1937 when the majority of road construction was actually paid for from local and general taxation.
The ring fenced, hypothecated tax wasn't enough so the government scooped-up the income and dumped it into general taxation.
Today Liberals are having another go. They want a tax hike, hypothecated, to keep the NHS afloat. They've assembled a group of the usual suspects to endorse the idea.
Regular readers will know, one way or another, I've been saying for a couple of years; one push, two-pence on tax, for three years to get the NHS back... on both feet.
I have trailed the idea on radio phone-ins, telly, magazine and newspaper articles and at conferences. Always the answer from the public is the same;
'Yes, let's do it... provided it is used exclusively for health and doesn't give managers a pay rise'.
Ouch!
It is the one tax increase, in history, that might be popular! People go with the idea of a rescue package.
Everyone, except the Tories. For them to agree would be to admit the NHS needs rescuing. They can't do that for all the reasons that makes politics the dirty business it is and the DH press office look so stupid. No admission of failure is possible.
The Treasury whizz-kids will tell you a 1p rise in income tax would raise:
#�3.9bn this year,
#�4.5bn next
#�4.6bn in 2018-19.
Is it churlish to point out; the NHS needs �2bn a week to keep the lights on and the medicine cabinet full? An extra �4bn or so a year gives us �76m a week.
It's a Tesco policy; 'every little helps'.
Remember, we are facing a �22bn gap in finances by 2020-21.
Remember, also, we are in the cusp of the political party conference season. The idea is to make your lot look like a bunch of cool dudes, ready for government and the others look like a rag bag of idiots, tramps and thieves.
There is no doubt, a rescue package for the NHS will have electoral appeal. Coupled with, what I hear will be the other Liberal promise; offer a referendum on the terms of Brexit and I suspect their focus group research will tell them they are onto a winner.
Back in the real world; a hypothecated NHS tax would take a year, perhaps more, to yield any real cash. It has to be put in a finance bill, weave its way through a grudging Parliament, Treasury rules amended, the tax gathered, distributed on some basis and NHS allocations made.
How would rescue cash be spent? Undoubtedly it would help and be welcome but it's not enough to make a structural difference and NHS finances are in structural decline. The San-Andreas fault-line between resource and reality.
The key problem we are facing? Adult social care has collapsed. Care homes are closing, staff are leaving and the frail elderly abandoned to decline. In consequence the NHS is grinding to a halt. Social care needs the urgent rescue package... but there a few votes in that idea.
An NHS rescue package is a nice idea, I'm guilty of promoting it. My current fear is that it is too late. It is political populism. Think it through.
The answer to the NHS funding crisis is a rock solid commitment to get funding levels back to the EU average. The Tories will say that depends on a strong economy.
Other, austerity hit economies have managed it. Why can't we? It looks to me, more likely, it depends on strong commitment to the NHS.