alternative hoyer's solution
SCHOT at RULRHB.LEIDENUNIV.NL
Thu Apr 11 16:38:58 CDT 1996
----- Begin forwarded message 11-Apr-96
In January there was a lot of discussion on TAXACOM about the ingredient Arabic
gum for Hoyer's solution. At that time I was just trying to make a new solution
for our bryology department. Here's my solution:
METHODS USED TO MAKE ALTERNATIVE HOYER'S SOLUTION
Formula for alternative Hoyer's solution using powdered Arabic gum:
Arabic gum (powder) 40 g
Distilled water 80 ml
Glycerin 20 ml
Chloral hydrate 30 g *
Dissolve the Arabic gum in destilled water by stirring it on a magnetic stirrer
for 48 hours.
Add the glycerin and chloral hydrate.
Carefully heat the mixture (to about 60 degrees Celcius) and filtre it through
a Buchner funnel with a piece of clean, roughly woven cotton cloth, to remove
the biggest particles.
Pour the mixture into a tall narrow glass cylinder and let it rest for two
weeks so that the small particles sink to the bottom.
The top part which is an almost clear solution can now be used to mount mosses.
* The amount of chloral hydrate is a lot less than in the original Hoyer's
formula. This has the advantage that the mounted material doesn't become too
The use of powdered Arabic gum as done above has the disadvantage that the
final solution remains a little cloudy.
We found that we could still obtain granular Arabic gum from a chemical
supplier in the Netherlands. But it should be no problem to find a supplier in
your own country that distributes products from the firm "CHROMA gesellschaft".
Gummi Arabicum, granuliert CHROMA nr. 3G 112
from: Brunschwig chemie b.v.
1007 KE AMSTERDAM
Good luck with making your own moss mounting medium!
Bertie Joan van Heuven
2300 RA LEIDEN
EMAIL: IN%"HEUVEN at RULRHB.LEIDENUNIV.NL"
----- End forwarded message
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