Judy Seigel (jseigel@panix.com)
Fri, 15 Jan 1999 12:22:46 -0500 (EST)
On Fri, 15 Jan 1999, Wayde Allen wrote:
>
> I have been storing my solution in a brown glass bottle equiped with a
> glass eye dropper in the lid. They sell these at the local health food
> stores for about $0.60, and the eye dropper is handy for measuring
> out the solution.
Ah, Wayde -- 60 cents? Where are you, in 1950? A dropper bottle in any
self-respecting health food store around here is probably $1.50 minimum.
But I too love the dropper bottle, and use them for everything. They sure
beat pipettes & syringes -- and save water because no washing afterwards.
Yours are, I assume, the 2 ounce size? If they come larger, perhaps your
store will reveal the source? I got some 8 ounce a few years back I don't
think are made any more (or anyway Ginsberg Scientific has been *acquired*
and its stock trimmed in the dropper bottle department), but they are
great.
I find, by the way, that solutions keep surprisingly well thusly. You'd
think air would enter through the rubber part, but doesn't seem serious.
Over a 10 year period I've had that rubber go brittle in some -- bottles
containing acid solutions for the most part -- but not many. Though come
to think of it, that could be why my dichromate solution gets slower, it's
in a dropper bottle unrefrigerated the whole time. (If so, a small price
to pay, say I.)
But here's a dropper bottle tip, a claim I have no reason to doubt, made
by the one person I know who knows everything (and he knows who he is!):
If you want *precise* dropper measurements, the plastic stem kind are
probably better than the glass, because the glass is blown & can have
minor differences in aperture. The plastic is molded and identical. I
also once solved a formula failure when I realized that I'd been counting
drops in A & B but the 2 droppers (from non-matching bottles) were in fact
quite different-- 20 drops of A coming to about 50% more than 20 of B.
cheers,
Judy
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:42