by weight or volume? ... & preservative?

On Mon, 1 Dec 2003, Kerik wrote:

> Also, I'm curious what Sam means by a 1 part gum to 2 parts water. Is this
> by weight? I mix 300 gm of powdered gum to 1 liter of water and end up
> with slightly more than 1 liter of solution. If Sam is mixing 500 gm
> powder to 1 liter of water, then I presume his gum is more viscous than
> mine.

I was about to ask same question... I have some vintage "tears" of gum
arabic I'm going to turn into gum arabic in the interests of science, of
course. I recall 30%, but it didn't say by weight or volume.

The next question is, any suggestions about preservative? I have
salicilic acid, glyoxal, and a solution of 15% thymol. I used to use
formaldehyde -- 1 drop preserved 2 ounces forever, but that bottle is all
dried up. (I could I suppose use the residue, but that seems so
unscientific.) Meanwhile, has anyone used glyoxal instead?

J.
Received on Mon Dec 1 16:26:38 2003