Bubble Counter Fluid

[Ed Dumas <a4a48835 at telus_net>]

I was searching the net last night looking over deals on CO2 equipment
and the like, and came across a listing at one site for "Bubble Counter
Fluid". Supposedly it evaporates less than water. When I read that, I
realized that water would evaporate fairly quickly out of a bubble
counter. Does anyone out there have any idea what "Bubble Counter Fluid"
is? Is it worth investing in, or does the water take long enough to
evaporate that the fluid is not worth investing in? Is there a
alternative source for this fluid?

Thanks so much.

Ed