Re: [diatom_forum] Diatoms of the Arid Southwest
- A friend of mine produces excellent strews with the hydrogen peroxide /
potassium permanganate method. Often the strews are so clean that one
would think he uses the hot acid method. This is what he does:
Add HCl 30% to the sample (same volume as the sample); wait for 2 hrs
under occasional shaking/swirling;
Change water/rinse 4 to 5 times to remove HCl;
Add H2O2 (twice the volume of the sample). Heat to boiling, let it
gently boil for 2 to 3 hrs;
Add a saturated solution (in water) of KMnO4; one drop at a time.
Continue until the reaction has stopped. The sample is quite brown in color;
Add a milliliter or so of HCl, and then an equal amount of H2O2. This
removes the brown.
After this the usual washings.
All the best,
Op 30-4-2012 0:07, Richard Carter schreef:
> I have some of that peroxide, too. It hasn't worked all that well for me
> in the past, but I didn't boil for anywhere near 3 hours. I'll give it
> another try. Thanks for the tip!
> *From:* Rob Kimmich <kimmich46@...>
> *To:* email@example.com
> *Sent:* Sunday, April 29, 2012 2:38 PM
> *Subject:* Re: [diatom_forum] Diatoms of the Arid Southwest
> Maybe it's more than you need right now but H2O2 labeled 35% that I get
> at the health food store is producing satisfying results, at least for
> me. After the usual sieving I have been gently boiling samples for at
> least 3 hrs. Of course, there are multiple rounds of settling and
> swirling and diluting after. I am getting away with this in the house at
> the moment.
- Rob,A very stimulating post! I think your list of "questions" is excellent -- I'm sure each of us would offer different answers, but I also think that we each need to consider such questions.Thanks much,Dick
From: Rob Kimmich <kimmich46@...>
Sent: Wednesday, May 2, 2012 12:10 PM
Subject: [diatom_forum] Diatom Directions
Your note adds a lot to this great discussion of amateur study of diatoms. I have had your experience of using the SEM images to explain what I see with the LM. Dick has been one of my main sources for learning, too.
I see this discussion as what to do about distinguishing species, if that is possible for anyone, even with an SEM and a molecular lab. Even Dick, with the university library in Phoenix, is challenged, as he says. From my seat, the naming discussions have been cordial so far, e.g., Charles asking Dick to clarify a name as far as possible and Dick replying with a careful answer.
I certainly share the frustration I think I hear from Dick about pinning down an identification. I am finding that taking on any of this demands an acceptance of just not being able to know. Your point about not caring about naming accuracy may be the way to go here.
Hearing from you, Dick, and Dave helps me try to figure out what direction I want to take with all the images that I am accumulating and what it is I want to learn. Do I want to make species (or genus) lists of collections made? Am I happy with naming to genus? Do I want to learn more ecology? How important is sharing what I learn? (This forum has been a good place for that so far.) Do I want to continue developing LM technique?
By the way, would you be willing to ID some extant Mastogloia from the California desert?
On Wed, May 2, 2012 at 9:08 AM, klaus.kemp <klaus.kemp@...> wrote:
Due to a catastrophic meltdown of my hard drive on my laptop I have been kept out of the loop for some time, only to find that where evryone behaved and everyone gained something from the group I now find there are ripples of dissent] and over what NAMES!
May I remind you all that when I first joined the group I quoted my dear friend Bernard Hartley who on our first meeting said " We must/ should never fall out over a name". Now I find that there is dissent over naming of Diatoms, those of you old enough and studied Diatoms before the advent of TEM, SEM will remember the advocates of doom and gloom saying these would be the death of amateurs. As it turned out it was far from the truth with the instruments often showing details which had been seen by amateurs and in fact the reverse was also true we often went back to our slides after seeing an SEM photo and lo and behold we now see what has been missed before.
This brings me to my main point, do not throw your dummies out of the pram over such an issue as names of Diatoms, I was very intimidated by the naming of Diatoms until I joined this group and Charles has been instrumental in my starting to enjoy this, true my main reason for avoiding that was lack of literature and with each of Charles's posting I learned a little more.
Charles if you are serious about throwing in the towel would you consider exchanging emails with me and continue your excellent teachings? I would be honoured and do not give a damn about if you are up to date within the last hour.
FOR THOSE WHO THINK WE ARE OUT OF DATE "WHAT ARE YOU DOING HERE"?