insecticides used in herbaria

Jan Bosselaers dochterland at PANDORA.BE
Wed Feb 2 21:28:15 CST 2005

If it is mercuric chloride, the questions below can be answered as follows:
- it does not degrade
- it is extremely hazardous by inhalation (it sublimates readily) as
well as by touching; it can cause permanent neurological damage
For the record, our old botany professor told us a sad story about an
alcoholic herbarium technician who got severely handicapped because, for
years, he licked the brush with the alcoholic solution of mercuric
chloride he was about to apply...

Best regards,


>If you Google the following, "mercuric chloride" herbarium, (use the quotes) you'll find several links, including one to SPNHC, that address mercuric chloride as well as other pesticides.
>Gayle wrote:
>>Dear Taxacom members,
>>I have been going through old herbarium specimens (circa 1800's) borrowed from some prominent old herbaria.  Some of the specimens (algal) are coated with a black powdery substance and the paper is browned and disintegrating.  When I first pulled the specimens from their cabinets (some that hadn't been opened in many years), the toxic smell in the cabinets was pretty overwhelming.  Now that the specimens have been in boxes outside the cabinets, they no longer smell but some still have this powdery substance on them.
>>My question is:  What insecticides have been used by herbaria in the past?  Can people be affected by these toxins by smelling or touching them?  Do these toxins break down in time so that older herbarium specimens are safe?  If they are toxic, are there antidotes or safety measures for looking at these specimens?
>>Gayle Hansen
>>Hatfield Marine Science Center
>>Newport, Oregon
>>gayle.hansen at
>Richard J. Jensen              | tel: 574-284-4674
>Department of Biology      | fax: 574-284-4716
>Saint Mary's College         | e-mail: rjensen at
>Notre Dame, IN 46556    |

Dr. Jan Bosselaers
"Dochterland", R. novarumlaan 2
B-2340 Beerse, Belgium               tel / fax 32-14-615896
home: dochterland at  /  hortipes at
work: jbossela at
web: or

"You know I used to lose my mind, but now I'm old, now I'm free...
I see waves break in foams on my horizons, I'm shining..." The Chemical Brothers

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