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Posted By: wwh microtome - 12/07/03 12:59 AM
I've switched to a Conan Doyle story. Talking about a retired doctor:
". The
Doctor still read from cover to cover his Lancet and
his Medical Journal, attended all professional
gatherings, worked himself into an alternate state of
exaltation and depression over the results of the
election of officers, and reserved for himself a den of
his own, in which before rows of little round bottles
full of glycerine, Canadian balsam, and staining agents,
he still cut sections with a microtome, and peeped
through his long, brass, old-fashioned microscope at the
arcana of nature. "
It seems unlikely than many members have ever seen a microtome. Pieces of tissue have to be carefully preserved, then dehydrated, and the water replaced with paraffin, which gives it enough firmness to be sliced by the superkeen blade in the microtome, the thickness of the slices being very accuratedly controlled. Then they can be mounted on glass slides, stained, and examined under a microscope. That was my job in an Army medical laboratory in Manila during WWII.

Posted By: shanks Re: microtome - 12/07/03 07:51 AM
Hi Doc

Two interesting points to your posts.

1. You used the term paraffin, as opposed to the transpond kerosene. Nice one.

2. Your word, microtome, made think, a la Jackie and the scribblings thread above, of the root word that connects microtome and atom (that which cannot be cut). Are there any other common ones you can think of?

cheer

the sunshine warrior

Posted By: of troy Re: microtome - 12/07/03 01:22 PM
re:1. You used the term paraffin, as opposed to the transpond kerosene. Nice one.

i am confused-- i presumed that Dr bill meant paraffin ( a wax like petrolium distilate, commonly used (still) for making candles and wax seals on jellies and jams(which have enoung sugar and acid in them to naturally prevent the growth of boxalism, so they don't have to be 'water bath/steam processed, but can be 'canned' by being poured into sterile jars, and sealed with paraffin)
paraffin is a solid. Kerosene is an other petrolium distilate.. a liquid used to light 'storm latterns' and to clean built up wax off wood floors. (it can also be found in 'Lestoil' a heavy duty cleaner) (and like gasoline, kerosene itself doesn't burn(the liquid) , but its vapors (kerosene that has become gasous) do, and it vaporizes readily.--now that i think of it, its only paraffin gas that burns, but paraffin as a solid vaporizes less readily, so its safer)

i would think that a microtome 'solid' would be prepared by paraffin--which is solid at room tempeture, and not with kerosene which is liquid, and vaporizes more easily and could spontaniously combust in the heat of a lab.

i have seen microtomes in use (in HS, the bio lab had one for making slides. (the bio lab bought live frogs too, and pithed them as needed.. the school was large, (almost 5000 students at the time, my graduating class was over 1,400!) and like many NYC schools, well equipted.) but i didn'work in bio lab, and never actually used on. (the microtome, adn the biolab in general, was total off limits to students-- but i worked in bio office (service credits) and was in the lab once or twice with head of bio department.

so shanks what do you mean by 'paraffin', and dear dr bill, what do you mean? a waxy solid, or a volital liquid?



Posted By: wwh Re: microtome - 12/07/03 01:32 PM
Only one that occurs to me is "diatomaceous earth", deep deposits of tiny silicious remnants of diatoms. Very important industrially, as incredibly fine filter, e.g. to clarify beer. The "tom" part is not so obvious.
Webster's 1913 Dictionary

Definition: \Di"a*tom\, n. [Gr. ? cut in two. See {Diatomous}.]
1. (Bot.) One of the Diatomace[ae], a family of minute
unicellular Alg[ae] having a siliceous covering of great
delicacy, each individual multiplying by spontaneous
division. By some authors diatoms are called
Bacillari[ae], but this word is not in general use.

2. A particle or atom endowed with the vital principle.

The individual is nothing. He is no more than the
diatom, the bit of protoplasm. --Mrs. E. Lynn
Linton.





Posted By: wwh Re: microtome - 12/07/03 01:45 PM
Dear of troy: We used the same paraffin you use for sealing jelly jars, it was dissolved in chloroform to enable it to penetrate the tissues. Incidentally, though hazardous, the waste mixture of chloroform and paraffin made a very powerful paint remover for refinishing old furniture.
The name "paraffin" was given because there are no unsaturated carbon atoms to permit ready chemical reaction, and the chain is very long, making it a solid at room temperature. Which reminds me, some anal orifice in Army who knew nothing about the process, sent us to tropics with paraffin with melting point so low it was very soft in Manila. I had to hold an ice-cube to surface of tissue block just before cranking the microtome. Made my work a lot harder. I was lucky that I had Servel type refrigerator to make ice cubes. Reminds me, I used to see bombers overhead doing nothing but circling high up, to make ice for officer's mess at Air Force Messes. That was expensive ice.

Posted By: wwh Re: microtome - 12/07/03 03:42 PM
Dear shanks: I thought of "tome" meaning a large old book, but dictionary says etymology uncertain. The next thing tha popped into my few functional cerebral cortical neurones was "tomalley,aka tomali" the equivalent of the liver in a lobster. I have eaten it, but with no particular enjoyment.
Now I find that health authorities recommend avoiding it, because it may have mercury, dioxins,etc. in it.
"Lobster Tomalley: No Consumption. While there is no known safety considerations when it comes to eating lobster meat, consumers are advised to refrain from eating the tomalley. The tomalley is the soft, green substance found in the body cavity of the lobster. It functions as the liver and pancreas, and test results have shown the tomalley can accumulate contaminants found in the environment. "

Posted By: shanks Re: microtome - 12/07/03 05:05 PM
Dear Helen

Perhaps this will clear up matters:

http://www.bartleby.com/68/2/3502.html

What US'ns call paraffin, I think we call paraffin wax.

cheer

the sunshine warrior

Posted By: shanks Re: microtome - 12/07/03 05:08 PM
Well, the CAT-scan is another example I can think of - the T standing for tomography, which I presume means a picture of 'slices', as CAT scans are wont to produce.

There must be others... mutter... mumble...

Posted By: Bingley Re: microtome - 12/09/03 05:32 AM
Appendectomy is the obvious one. Onelook's list of ectomies:

http://www.onelook.com/?w=*ectomy&ls=a

Bingley
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