<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">Gretchen,</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span>I was hoping that a botanist might respond on the list with a recommendation for you (botany is not my specialty). I can tell you that the original Kew mixture was 53 percent industrial
methylated spirits (IMS, which is ethyl alcohol containing 9 percent water and
2–4 percent methanol), 37 percent water, 5 percent formalin (“dilute
formaldehyde”), and 5 percent glycerol (Forman and Bridson 1989). <span></span></span></p>
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span><span> </span></span></p>
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span>A note in the second edition of <i>The Herbarium Handbook</i>
(1992) stated that due to controls on hazardous chemicals, the original formula
at Kew had been withdrawn and replaced by a mixture of “70% alcohol (ethanol,
or ethanol + trace of methanol), 29% water and 1% glycerol. If using 90%
strength Industrial Methylated Spirit (IMS) the mixture is 78% IMS, 21% water
and 1% glycerol. With different strengths of IMS the proportions must be
adjusted accordingly” (Forman and Bridson 1989, 210). <span></span></span></p>
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span><span> </span></span></p>
<p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span>In the third edition (Bridson and Forman 1998) the Kew mixture
recipe was ten parts IMS, one part formalin, one part glycerol, and eight parts
water.</span></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif">The Kew mixture was supposed to help preserve the color in plants. If your concern is just to preserve flowers sufficiently for them to be dissected, you might try 70% ETOH, with no other additions. If the specimens are not intended to be saved as museum specimens, you could use denatured 70% ETOH, which is considerably less expensive.</p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif">Hope this helps.</p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif">--John</p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in 0in 0.0001pt;line-height:normal;font-size:11pt;font-family:"Calibri",sans-serif"><span><span></span></span></p>
</div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif">John E. Simmons<br>Writer and Museum Consultant</span></font></div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif">Museologica<br><i>and</i><br>Associate Curator of Collections<br>Earth and Mineral Science Museum & Art Gallery<br>Penn State University<br><i>and</i><br>Investigador Asociado, Departamento de Ornitologia<br>Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima</span></font><br></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, May 7, 2021 at 4:37 PM Gretchen Meier <<a href="mailto:gameier@d.umn.edu">gameier@d.umn.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi there!<div>Is there a recommended ETOH concentration for preserving flowers for later dissection? In a pinch, I've used cheap vodka (about 40%) but I'm not sure I want to bring that into a classroom. Any suggestions?<br><div><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr">Gretchen Meier (<i>she/her/hers</i>)</div><div dir="ltr"><div>Olga Lakela Herbarium (DUL)</div><div>University of Minnesota Duluth</div><div><a href="mailto:gameier@d.umn.edu" target="_blank">gameier@d.umn.edu</a></div><div>218.726.6542</div><div><br></div><div><i>Naturum expellas furca, tamen usque recurret - Homer </i></div><div>'you may drive nature out with a pitchfork, but she will come hurrying back'</div><div><span style="white-space:pre-wrap"><br></span><div><br><br><br></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
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